also: サービス・エース
noun
In tennis, volleyball, and similar sports, a serve that is not touched by the opponent and directly scores a point.
from English service ace
彼は試合で10本のサービスエースを決めた。
He hit 10 aces in the match.
エース can refer to an ace in cards, a star player, or an ace serve in context, while サービスエース specifically means an ace serve.
Loanword from English 'service ace'.