diff --git a/third_party/blink/renderer/core/paint/paint_layer.cc b/third_party/blink/renderer/core/paint/paint_layer.cc
--- a/third_party/blink/renderer/core/paint/paint_layer.cc
+++ b/third_party/blink/renderer/core/paint/paint_layer.cc
@@ -1480,10 +1480,18 @@ PaintLayer* PaintLayer::HitTestLayer(
             recursion_data.location) &&
         GetLayoutBox()->HitTestOverflowControl(
             result, recursion_data.location, layer_fragments[0].layer_offset)) {
-      if (z_offset && local_transform_state) {
-        *z_offset = ComputeZOffset(*local_transform_state);
+      // The overflow controls participate in the same preserve-3d depth-sort
+      // as the foreground/background paths below: only update the running-max
+      // *z_offset and report a hit if we are in front of the previously
+      // recorded sibling. Otherwise a behind-in-z scroller's resizer can
+      // clobber the depth-sort and let an occluded later sibling win,
+      // defeating IntersectionObserver-v2 / PEPC occlusion checks.
+      if (IsHitCandidateForDepthOrder(
+              this, false, z_offset,
+              container_transform_state ? container_transform_state
+                                        : local_transform_state)) {
+        return this;
       }
-      return this;
     }
   }