play one's ace
play one's trump card

When the king appeared, it was an easy matter to play the ace and another trump.

He would of course have played the ace if West had shown out on the second round, but that was most unlikely.

East was happy to win with the king, but had nothing better to do than play the ace and another diamond.

Instead he shifted to diamonds, playing the ace and the jack.

South would have to play the ace and another heart, making his contract.

Beginners in the East position almost always play the ace, which is usually wrong.

Playing the ace and another spade would have been no better.

When he played the ace on the first trick instead of the 10, the defense became difficult.

When the queen won he played the ace hoping the king would appear.

The best West can do after winning is to play the ace and another club.