South tried three no-trump, vulnerable, based on his spade spots, expecting the suit to produce three tricks.
West’s spade eight lead went to the queen and ace. Declarer naturally led out the diamond king next, West winning with the ace in order to continue spades. East won that with the king and got out safely with a spade as West let go of a club and dummy a diamond.
South had eight tricks now, nine if the diamonds came in, but alas — when he played a diamond to the jack, East discarded a spade. What now?
The club suit could hardly provide a second trick by force, given that East had not made a Michaels cue bid to show both majors, so declarer had just one chance for his contract. If East held the club king and queen, he could be endplayed in the suit, but only if the majors were stripped away first.
Thus, declarer led a diamond to the queen as East shed another spade. Now South cashed the last spade, dummy discarding a heart. East also had to discard a heart to keep clubs guarded. However, declarer next led a heart to dummy’s eight. East won and got out with a heart, but now South could take the ace and king, removing East’s exit cards, before calling for a low club. East went in with the club queen and had to lead into South’s split tenace at the finish.
It would not have helped West to insert the heart queen on the first heart; declarer could just play three rounds of the suit. West should have played a club through dummy when in with the diamond ace.