You cannot do any better by winning the king on the heart return - the same problem exists. If you exit a spade after going up with the ♥K, the defenders will cash their spade tricks, the ♥Q, and lock in in dummy with a diamond. The solution is to unblock the ♥K under the ace! This has the effect of creating a trump entry to hand, in order to take a club finesse. Later, if the defenders do not play diamonds, you can ruff a club back to hand and take the diamond finesse.

The only other noteworthy variation is when declarer sticks in the ♦J from dummy. If declarer exits with a spade at trick two, and East wins the ♠Q and backs a trump to West's ace, unblocking the ♥K would once again result in success. In this scenario, declarer can survive even without unblocking the ♥K. He should win the heart return with the king though, cash his diamond honors, and exit with a spade; the defenders will then be forced to provide an entry to the South hand.

Analysis:
Bridge Baron's double dummy solver asserts that unblocking the ♥K at trick four is essential for the success of the contract.

Bridge Baron's Line of Play
Bridge Baron won the opening diamond lead in dummy with the king and correctly played a spade. When East won the trick with the ♠Q and played a heart to West's ace, Bridge Baron correctly unblocked dummy's ♥K under dummy's ace.
Par Contract Analysis:
The par contract on this deal is 2♠ by East-West. While it appears as if there are six losers in 2♠, North will be endplayed at some stage, and will have to lead away from one of his honors.

Bridge Baron deal No : N2064-47950-82105-84882-59676-94090