Problem

THE AUCTION:

North opened with 1♣. East overcalled 3♦ (weak, 6-8 diamonds). South bid 3♥. West passed, so North and South had an unhindered opportunity to explore slam possibilities. North supported hearts – 4♥. South bid 4♠, first round control in spades. North showed first round control in hearts with 4NT. South bid 5♦ (first round control in diamonds), North 6♣ (first round control in clubs). South showed second round control in diamonds with 6♦, North declared 6♥.

Can South win 12 tricks or is there a possibility for defense to defeat the contract?

West led the ♦3.

Vul: None

Contract: 6♥ by South