I, Cliff, was West when Declarer played this hand very well. South opened 1H and West bid 2NT (normally showing 5-5 in the minors).

North bid 4H, East 5D and South decided to go to 5H rather than double 5D. N/S were vulnerable and E/W not, so 5D would need to go down 4 tricks to give a better score than making a vulnerable game. In fact E/W should make 9 tricks in diamonds, so even 6D doubled would not have been as good for N/S as making game. I, West, decided we had a good chance of defeating 5H, so did not bid 6D. This hand however is an example of the 2NT bid giving away too much information if you subsequently defend. Declarer was able to make one more trick than he might have done without the benefit of that information. West led the DA and another diamond which was ruffed in Dummy.

Declarer played 2 rounds of trumps only, and then led a low club towards Dummy's CJxxx. If West wins the CK Declarer has 11 tricks, but West ducked and the CJ won the trick. Declarer now cashed SA and SK, hoping that the SQ would drop (assuming West's distribution was 2-1-5-5). He continued with a low spade, throwing West in to lead a club into CAQ or a diamond for a ruff and discard. 11 tricks made. 

Of course, I should have dropped the SQ under the SK, to avoid the throw-in and hoping East had the SJ. (I thought of it immediately after not doing it!) But since South had the SJ it would not have helped on this hand. 

Two points of interest are:-

Declarer could be certain that West had the CK, and almost certainly the SQ, from the bidding and the fact that he led a low diamond at trick 2. (Hence East had the DK.)

Declarer was fairly safe in leading a club towards the CJ, even if West did have 5 clubs. It is most unlikely that West would win the CK and lead another club for East to ruff.