Accurate tennis serves an opponent fails to touch (4)

I believe the answer is:

aces

(Other definitions for aces that I've seen before include "Winning serves" , "Ones or elevens in cards" , "Two will make deuce" , "passes with flying colours in US" , "wartime pilots?" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.