diff --git a/apps/desktop/src/components/layout/ContentArea.vue b/apps/desktop/src/components/layout/ContentArea.vue
index 9d07c34531..27d1f68afd 100644
--- a/apps/desktop/src/components/layout/ContentArea.vue
+++ b/apps/desktop/src/components/layout/ContentArea.vue
@@ -2103,6 +2103,7 @@ defineExpose({
                           class="group/result-run inline-flex h-7 shrink-0 select-none items-center overflow-hidden rounded-md border transition-colors"
                           :class="run.active ? 'border-border bg-background text-foreground shadow-sm' : 'border-transparent text-muted-foreground hover:border-border/70 hover:bg-background/70 hover:text-foreground'"
                           @contextmenu="onContextMenu"
+                          @mousedown.middle.stop.prevent="removeResultRun(run.id)"
                         >
                           <button
                             type="button"
@@ -2114,6 +2115,7 @@ defineExpose({
                             class="flex h-full select-none items-center gap-1 whitespace-nowrap pl-2.5 pr-1 text-xs font-medium outline-none focus-visible:bg-accent focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring/50"
                             @click="selectResultRunFromTab(run.id)"
                             @keydown="onResultRunTabKeydown($event, runIndex)"
+                            @mousedown.middle.stop.prevent="removeResultRun(run.id)"
                           >
                             <Pin v-if="run.pinned" class="h-3 w-3 shrink-0 fill-current text-primary" />
                             {{ run.title || run.sourceLabel || resultRunFallbackLabel(run.sequence) }}
@@ -2132,7 +2134,7 @@ defineExpose({
                     </div>
                   </div>
                 </div>
-                <div v-else-if="showResultRunSelector" class="min-w-0" :class="{ 'flex-1': visibleResultItems.length === 0 }">
+                <div v-else-if="showResultRunSelector" class="min-w-0" :class="{ 'flex-1': visibleResultItems.length <= 1 }">
                   <DropdownMenu>
                     <DropdownMenuTrigger as-child>
                       <Button variant="ghost" size="sm" class="h-6 max-w-48 gap-1 px-2 text-xs">
@@ -2142,7 +2144,7 @@ defineExpose({
                     </DropdownMenuTrigger>
                     <DropdownMenuContent align="start" class="w-48">
                       <CustomContextMenu v-for="run in resultRuns" :key="run.id" :items="() => resultRunContextMenuItems(run)" v-slot="{ onContextMenu }">
-                        <DropdownMenuItem class="flex items-center gap-2 pr-1" @select="selectResultRunFromTab(run.id)" @contextmenu="onContextMenu">
+                        <DropdownMenuItem class="flex items-center gap-2 pr-1" @select="selectResultRunFromTab(run.id)" @contextmenu="onContextMenu" @mousedown.middle.stop.prevent="removeResultRun(run.id)">
                           <Check v-if="run.active" class="h-3.5 w-3.5 shrink-0" />
                           <span v-else class="h-3.5 w-3.5 shrink-0" />
                           <Pin v-if="run.pinned" class="h-3 w-3 shrink-0 fill-current text-primary" />
@@ -2162,9 +2164,9 @@ defineExpose({
                   </DropdownMenu>
                 </div>
                 <div v-else-if="resultRuns.length > 0" class="min-w-0 flex-1" />
-                <span v-if="resultRuns.length > 0 && visibleResultItems.length > 0" class="mx-1 h-4 w-px shrink-0 bg-border" />
+                <span v-if="resultRuns.length > 0 && visibleResultItems.length > 1" class="mx-1 h-4 w-px shrink-0 bg-border" />
                 <ResultSetNavigator
-                  v-if="visibleResultItems.length > 0"
+                  v-if="resultRuns.length > 0 ? visibleResultItems.length > 1 : visibleResultItems.length > 0"
                   :key="`${activeTab.id}:${activeTab.activeResultRunId ?? 'current'}`"
                   :items="visibleResultItems"
                   :busy="resultBatchBusy"
@@ -2172,6 +2174,7 @@ defineExpose({
                   :active-index="activeTab.activeResultIndex ?? 0"
                   :active="activeOutputView === 'result'"
                   :display-mode="resultRunDisplayMode"
+                  :has-sibling-run-tabs="resultRuns.length > 0"
                   @select="selectResultItem"
                   @copy-sql="copySelectedResultSql"
                   @copy-query-sql="copySelectedResultQueries"
diff --git a/apps/desktop/src/components/layout/ResultSetNavigator.vue b/apps/desktop/src/components/layout/ResultSetNavigator.vue
index cf076604f0..267392a710 100644
--- a/apps/desktop/src/components/layout/ResultSetNavigator.vue
+++ b/apps/desktop/src/components/layout/ResultSetNavigator.vue
@@ -17,9 +17,11 @@ const props = withDefaults(
     busy?: boolean;
     canExportXlsx?: boolean;
     displayMode?: "tabs" | "list";
+    hasSiblingRunTabs?: boolean;
   }>(),
   {
     displayMode: "tabs",
+    hasSiblingRunTabs: false,
   },
 );
 const emit = defineEmits<{
@@ -159,7 +161,7 @@ function onListKeydown(event: KeyboardEvent, index: number) {
 </script>
 
 <template>
-  <div data-result-set-tabs-region role="group" :aria-label="t('tabs.resultSets')" class="flex h-full min-w-0 flex-1 items-center gap-1 overflow-hidden">
+  <div data-result-set-tabs-region role="group" :aria-label="t('tabs.resultSets')" class="flex h-full min-w-0 items-center gap-1 overflow-hidden" :class="hasSiblingRunTabs ? 'shrink-0 max-w-[50%]' : 'flex-1'">
     <template v-if="displayMode === 'list'">
       <div v-if="items.length > 0" class="flex min-w-0 items-center gap-1">
         <Popover v-if="items.length > 1" v-model:open="open">
diff --git a/apps/desktop/src/components/layout/__tests__/ContentArea.resultRuns.spec.ts b/apps/desktop/src/components/layout/__tests__/ContentArea.resultRuns.spec.ts
new file mode 100644
index 0000000000..7abb6333fa
--- /dev/null
+++ b/apps/desktop/src/components/layout/__tests__/ContentArea.resultRuns.spec.ts
@@ -0,0 +1,172 @@
+// @vitest-environment happy-dom
+import { createApp, defineComponent, h, nextTick, reactive } from "vue";
+import { createPinia, setActivePinia } from "pinia";
+import { createI18n } from "vue-i18n";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import type { QueryResult, QueryTab } from "@/types/database";
+
+vi.mock("@/components/editor/QueryEditor.vue", () => ({ default: { render: () => null } }));
+vi.mock("@/components/transfer/QueryResultTransferDialog.vue", () => ({ __esModule: true, default: { render: () => null } }));
+vi.mock("@/components/grid/DataGrid.vue", () => ({ default: { render: () => h("div", { "data-test": "data-grid" }) } }));
+
+import ContentArea from "../ContentArea.vue";
+import { useConnectionStore } from "@/stores/connectionStore";
+import { useQueryStore } from "@/stores/queryStore";
+
+const cleanups: Array<() => void> = [];
+afterEach(() => {
+  cleanups.splice(0).forEach((cleanup) => cleanup());
+  document.body.replaceChildren();
+  window.localStorage?.clear();
+});
+
+async function mountContentAreaWithRuns(options: { results: QueryResult[]; resultRuns?: NonNullable<QueryTab["resultRuns"]>; activeResultRunId?: string }) {
+  const pinia = createPinia();
+  setActivePinia(pinia);
+  const connection = { id: "mysql-1", name: "MySQL", db_type: "mysql" as const, host: "localhost", port: 3306, username: "root", password: "" };
+  useConnectionStore().connections = [connection];
+  const tab = reactive<QueryTab>({
+    id: "query-tab-1",
+    title: "Query 1",
+    connectionId: connection.id,
+    database: "app",
+    mode: "query",
+    sql: "SELECT 1",
+    isExecuting: false,
+    results: options.results,
+    result: options.results[0],
+    activeResultIndex: 0,
+    resultRuns: options.resultRuns,
+    activeResultRunId: options.activeResultRunId,
+  });
+  useQueryStore().tabs.push(tab);
+
+  const state = reactive({ view: "result" as "result" | "messages" });
+  const host = document.createElement("div");
+  document.body.appendChild(host);
+  const app = createApp(
+    defineComponent({
+      setup: () => () =>
+        h(ContentArea, {
+          activeTab: tab,
+          activeConnection: connection,
+          activeOutputView: state.view,
+          executableSql: "",
+          formatSqlRequest: null,
+          compressSqlRequest: null,
+          selectedSql: "",
+          cursorPos: 0,
+          resultOnly: true,
+          blockDangerousRedisCommands: false,
+          "onUpdate:activeOutputView": (_tabId: string, view: string) => {
+            state.view = view as typeof state.view;
+          },
+        }),
+    }),
+  );
+  app.use(pinia);
+  app.use(
+    createI18n({
+      legacy: false,
+      locale: "en",
+      messages: {
+        en: {
+          tabs: {
+            resultN: "Result {n}",
+            runN: "Run {n}",
+            resultRuns: "Result runs",
+            resultSets: "Result sets",
+            allResults: "All results ({count})",
+            removeRun: "Remove run {n}",
+          },
+        },
+      },
+      missingWarn: false,
+      fallbackWarn: false,
+    }),
+  );
+  app.mount(host);
+  cleanups.push(() => app.unmount());
+  await nextTick();
+  await nextTick();
+  return { host, state, tab };
+}
+
+describe("ContentArea result run tabs layout and middle-click close", () => {
+  const singleResult: QueryResult = {
+    columns: ["id"],
+    rows: [[1]],
+    affected_rows: 1,
+    execution_time_ms: 5,
+  };
+  const secondResult: QueryResult = {
+    columns: ["name"],
+    rows: [["Alice"]],
+    affected_rows: 1,
+    execution_time_ms: 3,
+  };
+
+  it("hides ResultSetNavigator when resultRuns exist and active run has a single result set", async () => {
+    const { host } = await mountContentAreaWithRuns({
+      results: [singleResult],
+      resultRuns: [
+        { id: "run-1", title: "Run 1", sequence: 1, sql: "SELECT 1", createdAt: 1, result: singleResult, results: [singleResult] },
+        { id: "run-2", title: "Run 2", sequence: 2, sql: "SELECT 2", createdAt: 2, result: singleResult, results: [singleResult] },
+      ],
+      activeResultRunId: "run-1",
+    });
+
+    const runTabsRegion = host.querySelector("[data-result-run-tabs-region]");
+    expect(runTabsRegion).not.toBeNull();
+    const runTabs = host.querySelectorAll("[data-result-run-tab]");
+    expect(runTabs.length).toBe(2);
+
+    // ResultSetNavigator is hidden because visibleResultItems.length <= 1
+    const resultSetRegion = host.querySelector("[data-result-set-tabs-region]");
+    expect(resultSetRegion).toBeNull();
+  });
+
+  it("shows ResultSetNavigator when resultRuns exist and active run has multiple result sets", async () => {
+    const { host } = await mountContentAreaWithRuns({
+      results: [singleResult, secondResult],
+      resultRuns: [
+        { id: "run-1", title: "Run 1", sequence: 1, sql: "SELECT 1; SELECT 2;", createdAt: 1, result: singleResult, results: [singleResult, secondResult] },
+        { id: "run-2", title: "Run 2", sequence: 2, sql: "SELECT 3", createdAt: 2, result: singleResult, results: [singleResult] },
+      ],
+      activeResultRunId: "run-1",
+    });
+
+    const runTabsRegion = host.querySelector("[data-result-run-tabs-region]");
+    expect(runTabsRegion).not.toBeNull();
+
+    // ResultSetNavigator is shown because visibleResultItems.length > 1
+    const resultSetRegion = host.querySelector("[data-result-set-tabs-region]");
+    expect(resultSetRegion).not.toBeNull();
+    expect(resultSetRegion?.classList.contains("shrink-0")).toBe(true);
+    expect(resultSetRegion?.classList.contains("max-w-[50%]")).toBe(true);
+  });
+
+  it("closes result run on middle click on the result run tab", async () => {
+    const { host } = await mountContentAreaWithRuns({
+      results: [singleResult],
+      resultRuns: [
+        { id: "run-1", title: "Run 1", sequence: 1, sql: "SELECT 1", createdAt: 1, result: singleResult, results: [singleResult] },
+        { id: "run-2", title: "Run 2", sequence: 2, sql: "SELECT 2", createdAt: 2, result: singleResult, results: [singleResult] },
+      ],
+      activeResultRunId: "run-1",
+    });
+
+    const queryStore = useQueryStore();
+    const removeSpy = vi.spyOn(queryStore, "removeResultRun").mockResolvedValue(true);
+
+    const runTabs = host.querySelectorAll<HTMLButtonElement>("[data-result-run-tab]");
+    expect(runTabs.length).toBe(2);
+
+    // Middle click on run-2 (button: 1)
+    const middleClickEvent = new MouseEvent("mousedown", { button: 1, bubbles: true, cancelable: true });
+    runTabs[1]!.dispatchEvent(middleClickEvent);
+    await nextTick();
+
+    expect(removeSpy).toHaveBeenCalledWith("query-tab-1", "run-2");
+  });
+});
diff --git a/apps/desktop/src/components/layout/__tests__/ResultSetNavigator.spec.ts b/apps/desktop/src/components/layout/__tests__/ResultSetNavigator.spec.ts
index 00200de6fa..9a79c11219 100644
--- a/apps/desktop/src/components/layout/__tests__/ResultSetNavigator.spec.ts
+++ b/apps/desktop/src/components/layout/__tests__/ResultSetNavigator.spec.ts
@@ -12,7 +12,7 @@ afterEach(() => {
   document.body.replaceChildren();
 });
 
-async function mountNavigator(inputResults?: QueryResult[], canExportXlsx = true, displayMode: "tabs" | "list" = "tabs", activeIndex = 1) {
+async function mountNavigator(inputResults?: QueryResult[], canExportXlsx = true, displayMode: "tabs" | "list" = "tabs", activeIndex = 1, hasSiblingRunTabs = false) {
   // Include a non-tabular result so ordinal and storage index are different.
   const results = inputResults ?? ([{ columns: [], rows: [] }, ...Array.from({ length: 100 }, (_, i) => ({ columns: ["value"], rows: [[i + 1]], sourceStatement: `SELECT ${i + 1} AS value` }))] as QueryResult[]);
   const select = vi.fn();
@@ -21,7 +21,7 @@ async function mountNavigator(inputResults?: QueryResult[], canExportXlsx = true
   const exportXlsx = vi.fn();
   const container = document.createElement("div");
   document.body.append(container);
-  app = createApp(ResultSetNavigator, { items: tabularResultItems(results), activeIndex, active: true, canExportXlsx, displayMode, onSelect: select, onCopySql: copySql, onCopyQuerySql: copyQuerySql, onExportXlsx: exportXlsx });
+  app = createApp(ResultSetNavigator, { items: tabularResultItems(results), activeIndex, active: true, canExportXlsx, displayMode, hasSiblingRunTabs, onSelect: select, onCopySql: copySql, onCopyQuerySql: copyQuerySql, onExportXlsx: exportXlsx });
   app.use(
     createI18n({
       legacy: false,
@@ -239,4 +239,19 @@ describe("large result-set navigation", () => {
     expect(button.textContent?.trim()).toBe("Result sets");
     expect(button.querySelector("svg")).toBeNull();
   });
+
+  it("uses flex-1 when hasSiblingRunTabs is false or omitted", async () => {
+    const { container } = await mountNavigator();
+    const region = container.querySelector("[data-result-set-tabs-region]")!;
+    expect(region.classList.contains("flex-1")).toBe(true);
+    expect(region.classList.contains("shrink-0")).toBe(false);
+  });
+
+  it("constrains width with shrink-0 max-w-[50%] when hasSiblingRunTabs is true", async () => {
+    const { container } = await mountNavigator(undefined, true, "tabs", 1, true);
+    const region = container.querySelector("[data-result-set-tabs-region]")!;
+    expect(region.classList.contains("shrink-0")).toBe(true);
+    expect(region.classList.contains("max-w-[50%]")).toBe(true);
+    expect(region.classList.contains("flex-1")).toBe(false);
+  });
 });