When a hand looks too easy, beware. Win the ♥K and play the ♦A (key play), ruff a diamond high and cross to dummy with a spade. If both follow, draw a second trump and claim. Dummy’s club goes off on the ♥Q and you can ruff dummy’s two remaining diamonds.
Say, however, that someone shows out on the spade. Ruff another diamond high, cross to the ♣A, ruff dummy’s last diamond high, return to dummy with a trump and draw the two remaining trumps. Dummy’s club goes off on the ♥Q.
What have you safeguarded against by not playing a trump at trick two? The actual layout for one thing:
Say you win the ♥K and play a high spade from your hand and someone shows out. Now if you revert to diamonds, it could be too late. Say you cash the ♦A and ruff a diamond low. (You can’t afford to ruff high if West has three trumps as you need to ruff the other two diamonds high). Cross to a spade, ruff a diamond high, cross to the ♣A and ruff dummy’s last diamond with your last trump, an honor. Now you have to hope both hearts cash. Sorry.
Also, it is better to cross to the ♣A before ruffing dummy’s last diamond. If one opponent started with a 3=6=3=1 pattern, he will discard his club on the fourth diamond and now you can’t get to dummy to draw trumps.