At trick one you must be on the ball. With AK74 you would normally win first trick with the king and then play the Ace. Here however you have to give declarer a losing option.

Presumably declarer has some sort of Diamond stopper for his 2NT and it must be flimsy possibly Q10X and partner must have the Jack or 10 for his lead. Therefore at trick one you win with the Ace and then fire a low one back hopefully giving declarer the illusion that you started life with AJX and partner has KXXX  and  declarer will try his 10.

Declarer tries the 10 and partner almost falls off his chair when his Jack holds. A Diamond comes back and the defence takes the first five tricks and you earnt 10 imps in a  recent Teams of Four Match.

You can also view  watch the following movie to see how the hand pans out. (You need bridgvu.exe programme  or BridgeBase programme on your machine already to view it ) and it is available free from

http://www.haroldschogger.com/videos.htm