A hand very similar to this came up in the Camrose: I've taken it from Andy Robson's column in today's Times. South's 2 opening was more constructive than a traditional weak two, so when he next showed a non-minimum hand with a club feature, North had no difficulty bidding 6
West found the heart lead against 6, to the jack and queen. East switched to a club, won in dummy. Declarer, Tom Townsend, must not have fancied his chances when West discarded on the second spade, but surprisingly West had a singleton club too, so declarer could ruff two hearts and take four rounds of clubs before crossing to the ace and king of diamonds for the trump coup.
I'm surprised by East's club switch at trick two - Robson comments that East sensed "a lack of concern in declarer's manner". Fair enough, but then why switch to a club? If the ace of hearts isn't a winner, the only other way to beat the contract will be with a trump trick, so East should switch to a diamond to take out a late entry to dummy. To play the trump coup, declarer needs to take four rounds of clubs, ruffing two hearts along the way, before entering dummy. After a diamond switch, the only late entry to dummy is the second round of trumps, so declarer would have to play on clubs before discovering the bad trump break. Since this is a good idea only if West has two black singletons, and goes off any other time clubs are 4-1, it would be a remarkable view - East's diamond switch is suspicious, but could just as well be a bluff.
But it does take some imagination to place declarer with the 6-5 hand where the diamond switch may gain. And it needs West to have the QJ of diamonds too, or the switch sets up two diamond discards, so declarer no longer needs to take four clubs tricks and the trump coup operates routinely. East may have supposed that in that case West would have preferred a diamond lead. It's time to confess that I've swapped the five and jack of diamonds from the actual deal.
Incidentally, in the other room South opened 1, West made a (very) weak jump overcall in diamonds, and North bid 6NT. East led a diamond, and with eleven top tricks declarer chose to play East for the ace of hearts, making the contract on a strip squeeze.
Update: I checked with Tom, who points out that on the actual deal, rather than my invention, he could make 6S with East holding 3 clubs and no Q, by taking a diamond finesse so as to be able to discard two clubs on dummy's diamonds. And also that the play in 6NT described by Robson was dreamt up for the entertainment of his readers. The truth is recorded under Match Five, Stanza 2, board 28, here.