diff --git a/packages/main/src/components/Modals/index.tsx b/packages/main/src/components/Modals/index.tsx
index c9ced506d8c..3b1d7c35e14 100644
--- a/packages/main/src/components/Modals/index.tsx
+++ b/packages/main/src/components/Modals/index.tsx
@@ -1,9 +1,11 @@
 'use client';
 
+import { useIsomorphicLayoutEffect, useSyncRef } from '@ui5/webcomponents-react-base/internal/hooks';
 import type { MutableRefObject } from 'react';
 import { createRef, useEffect, useSyncExternalStore } from 'react';
 import { createPortal } from 'react-dom';
 import { getRandomId } from '../../internal/getRandomId.js';
+import type { IModal } from '../../internal/ModalStore.js';
 import { ModalStore } from '../../internal/ModalStore.js';
 import type { DialogDomRef, DialogPropTypes } from '../../webComponents/Dialog/index.js';
 import { Dialog } from '../../webComponents/Dialog/index.js';
@@ -84,7 +86,7 @@ function showDialogFn(
     Component: Dialog,
     props: {
       ...props,
-      open: true,
+      open: false,
       onClose: (event) => {
         if (typeof props.onClose === 'function') {
           props.onClose(event);
@@ -129,7 +131,7 @@ function showPopoverFn(
     Component: Popover,
     props: {
       ...props,
-      open: true,
+      open: false,
       onClose: (event) => {
         if (typeof props.onClose === 'function') {
           props.onClose(event);
@@ -177,7 +179,7 @@ function showResponsivePopoverFn(
     Component: ResponsivePopover,
     props: {
       ...props,
-      open: true,
+      open: false,
       onClose: (event) => {
         if (typeof props.onClose === 'function') {
           props.onClose(event);
@@ -219,7 +221,7 @@ function showMenuFn(
     Component: Menu,
     props: {
       ...props,
-      open: true,
+      open: false,
       onClose: (event) => {
         if (typeof props.onClose === 'function') {
           props.onClose(event);
@@ -262,7 +264,7 @@ function showMessageBoxFn(
     Component: MessageBox,
     props: {
       ...props,
-      open: true,
+      open: false,
       onClose: (event) => {
         if (typeof props.onClose === 'function') {
           props.onClose(event);
@@ -301,7 +303,7 @@ function showToastFn(
     Component: Toast,
     props: {
       ...props,
-      open: true,
+      open: false,
       onClose: (event) => {
         if (typeof props.onClose === 'function') {
           props.onClose(event);
@@ -319,6 +321,32 @@ function showToastFn(
   };
 }
 
+// TODO: Temporary workaround for #9116 — the web component resolves its initial focus synchronously in the
+// `open` setter instead of when focus is applied. Remove once fixed upstream (UI5/webcomponents#14234).
+/**
+ * Renders a single modal and opens it only after mount, so the web component's `open` setter runs after all
+ * other props (e.g. `preventInitialFocus`) are applied. Setting `open` in props applies it too early.
+ */
+function ModalRenderer({ modal }: { modal: IModal }) {
+  const { Component, props, ref, container, id } = modal;
+  const [componentRef, modalRef] = useSyncRef(ref);
+
+  useIsomorphicLayoutEffect(() => {
+    const node = modalRef.current as (Element & { open?: boolean }) | null;
+    if (node && 'open' in node) {
+      node.open = true;
+    }
+  }, [modalRef]);
+
+  // @ts-expect-error: ref is supported by all supported modals
+  const element = <Component {...props} ref={componentRef} data-id={id} />;
+
+  if (container) {
+    return createPortal(element, container);
+  }
+  return element;
+}
+
 /**
  * Utility class for opening modals in an imperative way.
  *
@@ -344,15 +372,7 @@ export function Modals() {
     <>
       {modals.map((modal) => {
         if (modal?.Component) {
-          if (modal.container) {
-            return createPortal(
-              // @ts-expect-error: ref is supported by all supported modals
-              <modal.Component {...modal.props} ref={modal.ref} key={modal.id} data-id={modal.id} />,
-              modal.container,
-            );
-          }
-          // @ts-expect-error: ref is supported by all supported modals
-          return <modal.Component {...modal.props} ref={modal.ref} key={modal.id} data-id={modal.id} />;
+          return <ModalRenderer key={modal.id} modal={modal} />;
         }
       })}
     </>
diff --git a/packages/main/src/components/Modals/test/Modals.gallery.tsx b/packages/main/src/components/Modals/test/Modals.gallery.tsx
new file mode 100644
index 00000000000..07c6f95de30
--- /dev/null
+++ b/packages/main/src/components/Modals/test/Modals.gallery.tsx
@@ -0,0 +1,33 @@
+import { useState } from 'react';
+import { Button } from '../../../webComponents/Button/index.js';
+import { Modals } from '../index.js';
+
+export const ModalsPreventInitialFocus = () => {
+  const [opened, setOpened] = useState(false);
+  return (
+    <>
+      <Modals />
+      <Button
+        data-testid="open-dialog"
+        onClick={() => {
+          const { close } = Modals.showDialog({
+            preventInitialFocus: true,
+            headerText: 'Dialog Title',
+            onOpen: () => {
+              setOpened(true);
+            },
+            children: "I'm a Dialog!",
+            footer: (
+              <Button data-testid="dialog-close" onClick={() => close()}>
+                Close
+              </Button>
+            ),
+          });
+        }}
+      >
+        Open Dialog
+      </Button>
+      <span data-testid="opened-flag">{opened ? 'opened' : 'closed'}</span>
+    </>
+  );
+};
diff --git a/packages/main/src/components/Modals/test/Modals.spec.tsx b/packages/main/src/components/Modals/test/Modals.spec.tsx
new file mode 100644
index 00000000000..a0eda458b7b
--- /dev/null
+++ b/packages/main/src/components/Modals/test/Modals.spec.tsx
@@ -0,0 +1,19 @@
+import { expect, test } from '../../../../../../playwright/fixtures/gallery-fixtures.js';
+
+test.describe('Modals.showDialog', () => {
+  test('preventInitialFocus is applied before the dialog opens', async ({ mount, page }) => {
+    await mount('Modals/ModalsPreventInitialFocus');
+
+    await page.getByTestId('open-dialog').click();
+
+    // The `open` event fires only after the dialog applied its initial focus, so waiting
+    // for it guarantees the focus decision has already been made before we assert on it.
+    await expect(page.getByTestId('opened-flag')).toHaveText('opened');
+    await expect(page.locator('[ui5-dialog]')).toBeVisible();
+
+    // With preventInitialFocus, focus must not be moved into the dialog...
+    await expect(page.getByTestId('dialog-close')).not.toBeFocused();
+    // ...it stays on the opener instead.
+    await expect(page.getByTestId('open-dialog')).toBeFocused();
+  });
+});