South opened One Diamond and North responded Two Clubs (forcing to game in their methods). South reversed with Two Spades and, in no hurry, North stressed his club length. South's next bid of Three Spades made it clear that he held five spades and at least six diamonds and, after preference to his first suit, he went on to game.
West led !3 against Five Diamonds and was well satisfied when he saw dummy's trump holding. After winning with !A, declarer led a low trump and West complacently followed with his four. Had he been in a slam, South would have had no choice but to go up with the cae, but in only Five he finessed #6!
If this had lost, say to the nine, he would have been able to win the rturn, cash #A, and start running clubs, losing only two trump tricks. As it happened, the deep finesse paid off when East showed out.
Now declarer started on clubs, discarding spades. West ruffed the third round and led another heart, but South trumped, cashed 4A and ruffed a spade, then threw his last losing spade on the next club. West made only two trump tricks.
It would have been a different story if West had inserted #9 at trick two - and he should have seen what was happening - for then he must come to a third trump trick.
East-West game; dealer South
#A 7 6
2A K J 10 9 5 2
4Q 8 3 4K J 10 6
!K 9 7 3 !Q 10 8 6 5 2
#K J 9 4 #none
28 6 27 4 3
4A 9 7 4 2
#Q 10 8 5 3 2