break someone's serve
In tennis and related sports, win a game served by one's opponent, as in The only way he'll win the match is to break Bill's serve. The use of serve, from the earlier service, meaning “starting play” in these sports, dates from the early 1600s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.