diff --git a/src/AcDream.Core/Physics/PhysicsEngine.cs b/src/AcDream.Core/Physics/PhysicsEngine.cs
index 33d03db..08f062a 100644
--- a/src/AcDream.Core/Physics/PhysicsEngine.cs
+++ b/src/AcDream.Core/Physics/PhysicsEngine.cs
@@ -915,7 +915,12 @@ public sealed class PhysicsEngine
 
             resolveResult = new ResolveResult(
                 sp.CheckPos,
-                ResolveCellId(sp.GlobalSphere[0].Origin, sphereRadius, sp.CheckCellId),
+                // Phase W Stage 1: return the transition's SWEPT cell (retail SetPositionInternal
+                // reads sphere_path.curr_cell), not a static re-derive from the resting origin.
+                // ValidateTransition advances sp.CurCellId only on accepted moves / reverts on
+                // blocks, so push-back or standing still cannot flip it. SetCurrAndReturn keeps the
+                // W2a CellGraph.CurrCell write the render root consumes.
+                SetCurrAndReturn(sp.CurCellId),
                 onGround,
                 collisionNormalValid,
                 collisionNormal);
@@ -934,7 +939,9 @@ public sealed class PhysicsEngine
             uint partialCellId = sp.CheckCellId != 0 ? sp.CheckCellId : cellId;
             resolveResult = new ResolveResult(
                 sp.CheckPos,
-                ResolveCellId(sp.GlobalSphere[0].Origin, sphereRadius, partialCellId),
+                // Phase W Stage 1: prefer the swept cell; fall back to partialCellId only when
+                // sp.CurCellId is zero (transition never advanced — teleport or physics reset).
+                SetCurrAndReturn(sp.CurCellId != 0 ? sp.CurCellId : partialCellId),
                 partialOnGround,
                 collisionNormalValid,
                 collisionNormal);