Last Sept, we were on an award in Y on CX/IB using AA miles: MNL-HKG-LHR-MAD-TFN. We were only Golds but very pleasantly surprised to find ourselves upgraded to J on the HKG-LHR. We had run into HKG for sightseeing and had through boarding passes to LHR so didn't find out until we were actually boarding at the gate. The scanner beeped and a smiling lady handed us 2 new boarding passes for J! I thought I had died and gone to heaven! I put this in the AA forum because it was an AA award ticket, don't know if the mods want to move it?