This deal from the 2020 European Seniors Championship was reported in the Final Bulletin. The declarer, Victor Markowicz humbly pointed it out to me:  

Vul:None Dlr: East	KQ732  AQ942  K  K7
105  8  AQ86542  1086		J98  KJ765  1073  A3
	A64  103  J9  QJ9542

At both tables, West opened 3 in 3rd seat. North bid 4 for the majors and South's 4 bought the contract.

The singleton heart was led and both declarers won the A. A famous tip for declarer is that "when a preempter leads a side suit, it is usually a singleton".

Hoping for good black-suit splits, they cashed the KQ (good news) and then played the K.

At one table, East won the ace and the rest was easy. Declarer had the A to draw the last trump and run the clubs.

At the other table, East made a good play by ducking the K. Why does that matter? Declarer played another club, but look what happed. East won the ace, played a diamond to West's ace and got a club ruff for down 1 (a trick in each suit). The Bulletin reported this brilliant defense and left it at that.

Why was Victor (who won the event) humble? He was the declarer and pointed out to me that although East made a good play, declarer still should have prevailed.

How? After the K holds, declarer can see what might be coming (the club ruff). So, before playing the second club, he should play the K to cut communications. West wins the A, but the defense can do no more than to take their 3 top tricks (no club ruff).