At one table, South ruffed the third heart and East overruffed and returned the J.
Declarer won the club with the ace in hand and immediately played the Q. He was able to establish the long diamond in dummy and pitch his losing club.
East missed a chance for the defense. When he overruffed the dummy, he should return a trump. This will remove a vital entry and the contract would fail.
Declarer also missed an opportunity. On the third heart he should discard a club from dummy and now the defense cannot hurt him. Did you find that play?