Mark led the ♦J, declarer winning in hand with the ♦K. Since I cannot possibly want a diamond, I played the 2 (UDCA) to show an even number; probably four in this context from Mark's perspective.
Declarer played the ♠K and a spade up (I followed with the 6 and 7). Seeing North discard a low heart (encouraging) she panicked and played the ♠A. Declarer does best at this point by playing clubs. The heart position prevents us from running the suit, and she can escape for -2. However, declarer continued to misstep and cashed the two remaining diamonds.
Mark sensibly unblocked the ♦T on the 3rd round which created an entry for me. When declarer belatedly played a club, I hopped with the Ace. I cashed the ♠T and Q in that order, to tell partner I'm cashing spades and to save whatever winners he has left. The ♥9 hold partner I didn't possess anything in that suit, so when North won the Ace, he simply played a diamond back to my nine for a 2nd heart play and we claimed for down 5 - +250.
I don't think there is anything magical about this hand on defense, and its not something I would even brag about, but it illustrates the type of basic defense that you need to execute to do well in a matchpoint game.
Obviously declarer made many misplays. Surrendering control of trumps by not ducking a round was a serious error. She should start by leading a spade toward the Ace, and one back toward her hand, which is indicated due to the preempt. Or, she can start clubs sooner, or even concede a heart prior to cashing the two high trump. A competent declarer should make 10 tricks here.
Strangely, no one made 10 tricks. +140 was a shared top for NS. Someone doubled 4♠ and beat it 3, so our +250 was an 11 out of 12.