East opened One Heart, South overcalled with One Spade and West (rather sportingly) made a negative double to show length in the minor suits. However, North's jump to game ended the auction and West led !2 against Four Spades. East rather mechanically followed with the seven, making it clear to South that the lead was a singleton.
At one table, declarer led 4Q immediately - perhaps in a rush to get a heart ruff the defenders might crash their honours. West brooded for some time, but got it right when he played low. East won, South's top heart was ruffed with the ace of trumps, and now a club lead put East in to cash a heart and defeat the contract.
At the other table, South led a club at trick two. East won and returned !Q for West to ruff South's winner. Now, however, declarer lost only to the 4A (the king falling helplessly) and dummy's losing heart went away on #Q.
The second plan had worked better, but there was still a defence! Instead of ruffing with the deuce of spades, suppose that West uses his ace. He follows with a trump to the king and his partner can cash a heart. But then, who defends like that?