Take the South seat on this deal from the semifinals of the 2025 USA1 Senior Trials. After West has shown five spades, you reach four hearts and receive the diamond eight lead to the queen, king and ace. Play on.All four declarers at the event gave up a spade at trick two and should have been defeated from that point on. The trouble was that East won with the spade ace and returned a trump, after which declarer could score no more than seven trump tricks and two aces. Against the one successful declarer, Mark Lair, East made the mistake of splitting his club honors when declarer later crossed back to his hand in that suit, so Lair was subsequently unable to endplay East.What every declarer seemed to miss was the possibility of a legitimate endplay against East, who was likely to have all the outstanding minor-suit honors. Ruff two diamonds in dummy and then draw trumps, ruffing at most two spades along the way in order to retain control.To put East under pressure in this way, ruff a diamond at trick two, and only then give up a spade. Take the trump shift in dummy, ruff a spade and ruff another diamond. Ruff a second spade and then cash your hearts. In the four-card ending, you retain 10-7 in diamonds and A-x in clubs. East must keep two diamonds lest you duck out his jack, so he reduces to two clubs, whereupon the club ace and another club endplay him to give you the diamond 10.Note that this ending does not work unless South holds on to the club ace.