The best chance was to drop the queen of clubs in two rounds. South cashed the ace and king but West discarded a diamond on the second round to end declarer's hopes of this. However, South had another idea. If East held only two hearts, he might be end-played in the black suits and forced to give dummy the lead.
Pursuing this plan, South cashed his top hearts and continued with the ten of clubs to dummy's jack. East did his best by taking his queen and exiting with a club, but when dummy's last club was led he was in difficulties again. He was left with S10872. If he discarded the two, a low spade would force him to concede the last trick to the nine. So he discarded the seven, playing his partner for the six.
Declarer countered neatly by leading the nine of spades from dummy. East took his ten and cashed the eight . Now dummy's three won the last trick, as advertised.Reuse content