North’s 2 NT reply to the Strong Two was a “negative” showing 0-7 points. But he had a good bad hand, improving with every bid. He was easily worth the jump to 4 ♠ over South’s 3 ♥ rebid as he held the ace in his partner’s second suit and three-card support for his partner’s first suit.
West led ♦ A, followed with ♦ K, then switched to ♥ 4. Declarer won dummy’s ♥ A and correctly led ♥ 8. East pounced on it with ♠ 5, declarer following with ♥ 7, and switched to ♣ 10. Declarer rose with ♣ A, cashed ♠ AK drawing the four remaining trumps, then cashed ♥ KQ discarding dummy’s two remaining ♣s. He was able to trump ♣ 6 with dummy’s last trump and so make the remaining tricks and his contract.
It would have been entirely different if East had refrained from trumping ♥ 8 at trick four. Say he discards a ♣ Declarer wins ♥ Q and can do no better than draw two rounds of trumps then attempt to trump ♥ 7 with ♠ 8. East overtrumps with ♠ 9 and the defence wait for their ♣ trick.

ANDREW’S TIP: As a defender, don’t trump a low card.