diff --git a/web/package.json b/web/package.json
index 8be5818fbda..f7670618a7f 100644
--- a/web/package.json
+++ b/web/package.json
@@ -110,7 +110,7 @@
     "react-arborist": "^3.16.0",
     "react-aspen": "^1.2.0",
     "react-checkbox-tree": "^2.1.1",
-    "react-data-grid": "https://github.com/pgadmin-org/react-data-grid.git#8ddaa7bed99c8329e39b8ff37ba156f7fc8e85d4",
+    "react-data-grid": "https://github.com/pgadmin-org/react-data-grid.git#d9dccda1ff4bfc155b6893d0c0ff7585cf0bc101",
     "react-dnd": "^16.0.1",
     "react-dnd-html5-backend": "^16.0.1",
     "react-dom": "^19.3.0",
diff --git a/web/pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/index.jsx b/web/pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/index.jsx
index 432f8e10ad3..1003761a393 100644
--- a/web/pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/index.jsx
+++ b/web/pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/index.jsx
@@ -311,6 +311,19 @@ RowNumColFormatter.propTypes = {
   onSelectedColumnsChange: PropTypes.func,
 };
 
+/* Shift + mousedown on a cell extends the selected cell range, but on the
+ * row number column shift + click belongs to row selection (handled by
+ * RowNumColFormatter). Select the row number cell as a plain click would,
+ * so a cell range left over from earlier is cleared rather than kept
+ * alongside the selected rows.
+ */
+export function onCellMouseDown({column, selectCell}, e) {
+  if(column.key == ROWNUM_KEY && e.shiftKey) {
+    e.preventGridDefault();
+    selectCell();
+  }
+}
+
 function formatColumns(columns, dataChangeStore, selectedColumns, onColumnSelected, onSelectedColumnsChange, rowKeyGetter) {
   let retColumns = [
     ...columns,
@@ -465,6 +478,7 @@ export default function QueryToolDataGrid({columns, rows, totalRowCount, dataCha
         }}
         enableRangeSelection={true}
         rangeLeftBoundaryColIdx={0}
+        onCellMouseDown={onCellMouseDown}
         onCellKeyDown={({column, rowIdx, selectCell, mode}, e)=>{
           /* Enter should not be propagated to editor and should
           only be used to open the editor */
diff --git a/web/regression/javascript/sqleditor/QueryToolDataGridMouseDown.spec.js b/web/regression/javascript/sqleditor/QueryToolDataGridMouseDown.spec.js
new file mode 100644
index 00000000000..86b02c3fd8a
--- /dev/null
+++ b/web/regression/javascript/sqleditor/QueryToolDataGridMouseDown.spec.js
@@ -0,0 +1,55 @@
+/////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013 - 2026, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+//////////////////////////////////////////////////////////////
+
+// Shift + mousedown on a results grid cell extends the cell range, but on
+// the row number column it must select the cell as a plain click does, so
+// that row selection is not mixed with a left-over cell range.
+
+jest.mock('../../../pgadmin/tools/sqleditor/static/js/components/QueryToolComponent.jsx', () => {
+  const React = require('react');
+  return {
+    QueryToolContext: React.createContext(null),
+    QueryToolConnectionContext: React.createContext(null),
+    QueryToolEventsContext: React.createContext(null),
+  };
+});
+
+// The cell editors pull in ESM-only dependencies that Jest cannot load.
+jest.mock('../../../pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid/Editors', () => ({}));
+
+import {
+  onCellMouseDown, ROWNUM_KEY,
+} from '../../../pgadmin/tools/sqleditor/static/js/components/QueryToolDataGrid';
+
+function mouseDown(columnKey, shiftKey) {
+  const selectCell = jest.fn();
+  const e = {shiftKey, preventGridDefault: jest.fn()};
+  onCellMouseDown({column: {key: columnKey}, selectCell}, e);
+  return {selectCell, e};
+}
+
+describe('QueryToolDataGrid onCellMouseDown', () => {
+  it('selects the row number cell on shift + mousedown', () => {
+    const {selectCell, e} = mouseDown(ROWNUM_KEY, true);
+    expect(e.preventGridDefault).toHaveBeenCalled();
+    expect(selectCell).toHaveBeenCalled();
+  });
+
+  it('leaves shift + mousedown on a data cell to the grid', () => {
+    const {selectCell, e} = mouseDown('col1', true);
+    expect(e.preventGridDefault).not.toHaveBeenCalled();
+    expect(selectCell).not.toHaveBeenCalled();
+  });
+
+  it('leaves a plain mousedown on the row number cell to the grid', () => {
+    const {selectCell, e} = mouseDown(ROWNUM_KEY, false);
+    expect(e.preventGridDefault).not.toHaveBeenCalled();
+    expect(selectCell).not.toHaveBeenCalled();
+  });
+});
diff --git a/web/yarn.lock b/web/yarn.lock
index 9ae4d7952f0..60d4ea1a294 100644
--- a/web/yarn.lock
+++ b/web/yarn.lock
@@ -12407,13 +12407,13 @@ __metadata:
   languageName: node
   linkType: hard
 
-"react-data-grid@https://github.com/pgadmin-org/react-data-grid.git#8ddaa7bed99c8329e39b8ff37ba156f7fc8e85d4":
+"react-data-grid@https://github.com/pgadmin-org/react-data-grid.git#d9dccda1ff4bfc155b6893d0c0ff7585cf0bc101":
   version: 7.0.0-beta.58
-  resolution: "react-data-grid@https://github.com/pgadmin-org/react-data-grid.git#commit=8ddaa7bed99c8329e39b8ff37ba156f7fc8e85d4"
+  resolution: "react-data-grid@https://github.com/pgadmin-org/react-data-grid.git#commit=d9dccda1ff4bfc155b6893d0c0ff7585cf0bc101"
   peerDependencies:
     react: ^19.2
     react-dom: ^19.2
-  checksum: 10c0/531f86c950e4f656cc45f496f7d5f95aaf2c7e2884d864d7954456e531810e7a7d99d52ee984b4140f034fafdc3f601913b8aa0949c8a06df784716dda66f06c
+  checksum: 10c0/53bc16d319c07fe5a4b4450f6afbab06b6d8210aebca2724ab13d339bf523fafb41af26d0e4991d0270aede6796e29c8fd388e7555219043398e8387e2c14a35
   languageName: node
   linkType: hard
 
@@ -13098,7 +13098,7 @@ __metadata:
     react-arborist: "npm:^3.16.0"
     react-aspen: "npm:^1.2.0"
     react-checkbox-tree: "npm:^2.1.1"
-    react-data-grid: "https://github.com/pgadmin-org/react-data-grid.git#8ddaa7bed99c8329e39b8ff37ba156f7fc8e85d4"
+    react-data-grid: "https://github.com/pgadmin-org/react-data-grid.git#d9dccda1ff4bfc155b6893d0c0ff7585cf0bc101"
     react-dnd: "npm:^16.0.1"
     react-dnd-html5-backend: "npm:^16.0.1"
     react-dom: "npm:^19.3.0"