Another test as defender can’t harm?
You play a teamgame, sitting west you can see the following cards after this bidding.
You start the defense with a spade, the 10 holds the trick with partner playing the 6. Declarer plays the king, queen and low heart to the ace in south, east follows with the 7, 6 and 2. Next is a low club from south, can you count 4 defensive tricks?
The key is in your partners carding. He have played high-low in trumph and this should be a clear signal for the highest suit – diamonds. So your only hope for down 1 is 3 tricks in diamonds and 1 in clubs. So you play a LOW Diamond.
That was perfect defense, since the whole hand looked like this
Partner grab his ace and play back another diamond for your King and queen.
It would have been an easier defense if you started with the king of diamond. The next diamond to the ace would be followed by a club.