This deal is from an EBU duplicate where there are over 100 pairs competing.
West led a low heart against three diamonds, won by the ace in dummy.
South now played a spade to set up spade tricks, also attempting to get an entry to hand so that he could play the first diamond from hand in case West held singleton ace.
West won the spade ace and persevered with hearts ruffed by South who then played a diamond to the jack and another diamond won by West, who exited with a spade won in dummy. South ruffed a heart back to hand, drew the last trump and played a club to the queen. Now a heart ruff set up a long heart trick and South had the remainder, making eleven tricks for a 88% score on the board. Most declarers in diamonds only made ten tricks when they didn't set up the long heart trick.