The most common and most likely answer to this crossword clue is the 10 letter word TIEBREAKER
I've seen this crossword clue in The Times
T
I
E
B
R
E
A
K
E
R
More clues leading to the result TIEBREAKER
- What may decide winner of cup, about right after draw
- Make fast roller a time-saver at Wimbledon
- What decides winner of cup after match? That’s about right
- Final point speaks of wave crashing on a Phuket beach?
- Match decider ultimately in cup — might it be?
- Sound of Asian wave? It’s decisive
- Divorcee in decisive court action?
Buddy explains!

The straight part
We know that "a time-saver at Wimbledon" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a time-saver at wimbledon = tiebreaker.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TIEBREAKER mean?
TIEBREAKER noun- Something that is used to pick a winner from a tied situation.