Room for error

Playing a qualification heat for the national pairs today (in our district), two pairs was way ahead of the pack going into the last round. Q-ing was guaranteed, but finishing 2nd is never an option. The other pair was sitting out the last round (one pair didn't show up for the event), netting about 60% for the round. We were behind going in and needed therefore better than that to eke out a win. On the first board our opps bid a 25 hcp 3NT, after partner opened, collecting a normal 10 tricks. This proved too challenging for the field giving us a mere 20%.

We were playing the Swedish 2-way 1C system and on the last hand (2-session 1-day event) my partner, Håkan Nilsson, opened 1C showing 11-13 balanced or any 17+. Complete auction (all vul):

1C - (pass) - 1H - (2D);
2H - (2S) - 3C - X;
4H all pass

RHO took a while for his final pass and after the K of diamonds was led, this was the view:

AJ
K863
8754
A93

8652
AJ542
A
J54

Some aggressive bidding for sure, but we needed an 85+ % board. Technically, this looked like a very simple deal; 4H makes with trumps 2-2 or 3-1 with stiff Q and goes down otherwise. Instead of going after hearts immediately, I decided to open up spades and give West a chance to go wrong. 2 rounds of spades to East as West followed small and a diamond shift ruffed in hand. Another spade from hand and West fell from grace by ruffing in with the H 9 as I discarded a club from dummy.

Complete deal:

________AJ
________K863
________8754
________A93
63____________KQT92
Q97___________T
KQJT3_________962
KQ8___________T762
________8652
________AJ542
________A
________J54

Ruffing in with the actual holding was wrong (of course) and resulted in +620 and we won by a fraction at 61,5%.

Remember that people do more silly things at the end of a long day as long as you give them a chance. In the fashion of a Nike slogan: Just let them!

__________________________________________________
EDIT:
My good friend Anders Wirgren kindly (and of course correctly!) has pointed out that the hand always can be made legitimately if declarer plays for trumps 3-1. Crossruffing puts West in a very uncomfortable position with threats in both minors (what to discard when the final spade is led from hand).