diff --git a/apps/bench/src/__tests__/ag-grid-adapter.test.tsx b/apps/bench/src/__tests__/ag-grid-adapter.test.tsx
index 950a01e..7591e91 100644
--- a/apps/bench/src/__tests__/ag-grid-adapter.test.tsx
+++ b/apps/bench/src/__tests__/ag-grid-adapter.test.tsx
@@ -2,6 +2,7 @@ import { render, waitFor } from "@testing-library/react";
 import { describe, expect, test } from "vitest";
 
 import { AgGridAdapter } from "../ag-grid-adapter";
+import type { BenchInteractionPlan } from "../interaction-plan";
 
 const dataset = {
   columns: [
@@ -14,6 +15,35 @@ const dataset = {
   ],
 };
 
+const statusDataset = {
+  columns: [
+    { id: "id", header: "ID", wrap: false, widthPx: 80 },
+    { id: "status", header: "Status", wrap: false, widthPx: 160 },
+  ],
+  rows: [
+    { id: "1", status: "running" },
+    { id: "2", status: "stopped" },
+    { id: "3", status: "running" },
+    { id: "4", status: "idle" },
+  ],
+};
+
+function filterPlan(
+  mode: "filter-metadata" | "filter-text",
+  filters: Record<string, string>,
+): BenchInteractionPlan {
+  return {
+    focusedRowId: null,
+    filters,
+    mode,
+    probeColumnId: Object.keys(filters)[0] ?? "",
+    resultRowCount: 0,
+    rows: [],
+    selectedRowId: null,
+    sort: null,
+  };
+}
+
 describe("AgGridAdapter", () => {
   test("mounts and renders AG Grid public selectors", async () => {
     const { container } = render(
@@ -28,4 +58,41 @@ describe("AgGridAdapter", () => {
       expect(container.querySelector(".ag-root-wrapper")).not.toBeNull();
     });
   });
+
+  test("publishes the post-filter row count, not the full dataset size", async () => {
+    // Mirror the bench: mount first, let the grid become ready, THEN apply the
+    // interaction plan. (The flushSync timing in the adapter is what makes the
+    // count land inside the bench's settle window in Chromium; this jsdom test
+    // guards the onFilterChanged wiring and that the count is published.)
+    const { container, rerender } = render(
+      <AgGridAdapter
+        dataset={statusDataset as never}
+        runKey={0}
+        scriptName="filter-metadata"
+        interactionPlan={null}
+      />,
+    );
+    await waitFor(() => {
+      expect(container.querySelector(".ag-root-wrapper")).not.toBeNull();
+    });
+
+    rerender(
+      <AgGridAdapter
+        dataset={statusDataset as never}
+        runKey={0}
+        scriptName="filter-metadata"
+        interactionPlan={filterPlan("filter-metadata", { status: "running" })}
+      />,
+    );
+
+    // status === "running" matches 2 of 4 rows. Filtering is a pure
+    // client-side row-model operation in AG Grid (no layout required), so the
+    // displayed-row count must reflect the filter even in jsdom.
+    await waitFor(() => {
+      const section = container.querySelector(
+        '[data-benchmark-adapter="ag-grid"]',
+      );
+      expect(section?.getAttribute("data-bench-result-row-count")).toBe("2");
+    });
+  });
 });
diff --git a/apps/bench/src/ag-grid-adapter.tsx b/apps/bench/src/ag-grid-adapter.tsx
index b90a753..838547e 100644
--- a/apps/bench/src/ag-grid-adapter.tsx
+++ b/apps/bench/src/ag-grid-adapter.tsx
@@ -1,10 +1,12 @@
-import { useEffect, useMemo, useRef } from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
+import { flushSync } from "react-dom";
 import { AgGridReact } from "ag-grid-react";
 import {
   AllCommunityModule,
   ModuleRegistry,
   themeQuartz,
   type ColDef,
+  type FilterChangedEvent,
   type GridApi,
   type GridReadyEvent,
 } from "ag-grid-community";
@@ -78,6 +80,12 @@ export function AgGridAdapter({
   const apiRef = useRef<GridApi | null>(null);
   const onUpdateApiReadyRef = useRef(onUpdateApiReady);
   const onAutosizeReadyRef = useRef(onAutosizeReady);
+  // Post-filter displayed-row count, published as data-bench-result-row-count.
+  const [resultRowCount, setResultRowCount] = useState(dataset.rows.length);
+  // `onGridReady` fires asynchronously after mount; gating the interaction
+  // effect on this flag re-applies a filter/sort plan that is already present
+  // at mount once the grid API exists, rather than silently skipping it.
+  const [gridReady, setGridReady] = useState(false);
 
   useEffect(() => {
     onUpdateApiReadyRef.current = onUpdateApiReady;
@@ -94,6 +102,7 @@ export function AgGridAdapter({
 
   const onGridReady = (event: GridReadyEvent) => {
     apiRef.current = event.api;
+    setGridReady(true);
     const apply: ApplyBenchUpdates = (patches) => {
       const updates = patches.map((p) => ({ ...p }));
       event.api.applyTransaction({ update: updates });
@@ -142,13 +151,13 @@ export function AgGridAdapter({
       }
       api.setFilterModel(model);
     }
-  }, [interactionPlan, runKey]);
+  }, [interactionPlan, runKey, gridReady]);
 
   return (
     <section
       aria-label="AG Grid Community adapter"
       data-benchmark-adapter="ag-grid"
-      data-bench-result-row-count={String(dataset.rows.length)}
+      data-bench-result-row-count={String(resultRowCount)}
       style={{ display: "grid", gap: 12 }}
     >
       <header>
@@ -164,6 +173,17 @@ export function AgGridAdapter({
           columnDefs={columnDefs}
           rowHeight={ROW_HEIGHT}
           onGridReady={onGridReady}
+          onFilterChanged={(event: FilterChangedEvent) => {
+            // AG Grid renders rows imperatively, so the bench's settle loop
+            // records result_row_count the moment the filtered rows paint.
+            // A normal setState re-render lands a few frames later — after
+            // settle — so the bench would capture the stale pre-filter count.
+            // flushSync forces the attribute update synchronously with this
+            // event, landing it inside the settle window.
+            flushSync(() =>
+              setResultRowCount(event.api.getDisplayedRowCount()),
+            );
+          }}
           getRowId={(params) => String((params.data as { id: unknown }).id)}
         />
       </div>