South drew trump with the king and ace of hearts, unblocked the second spade winner and led a diamond for the king and ace. East returned a diamond but South rose with the queen and advanced the king of clubs for a ruffing finesse. The ace was ruffed away as declarer returned to hand by trumping a spade. Dummy's remaining diamond was discarded on the queen of clubs resulting in twelve tricks, N-S +480. A diamond would have been pitched from the table if West had declined to play the ace of clubs for another twelve tricks.
South's leap to three hearts disclosed a maximum with four hearts and North happily moved on to the major suit game since there was a tencard fit and he held a club void.
South elected to open 1NT despite holding 18 HCP but, if he opens one club, North will become the declarer in a heart contract. Should South rebid three or four hearts when partner responds in the major? I think that three hearts is sufficient where partner will definitely advance to game. Twelve tricks are a lock on this layout but it is rather doubtful than any pair would reach a small slam.