教练在最后时刻换上替补球员的决定堪称妙招，直接扭转了比赛局势。

The coach's decision to bring on the substitute in the final minutes was a ___masterstroke that turned the game around.

她在谈判中突然降低价格的策略真是个妙招，让对方措手不及。

Her sudden price drop during the negotiation was a ___masterstroke that caught the other party off guard.