Excellent service (3)
I believe the answer is:
ace
This clue is a double definition.
'excellent' is the first definition.
(I've seen this before)
'service' is the second definition.
(ace is a kind of service)
(Other definitions for ace that I've seen before include "Expert - winning serve" , "star" , "winner in court" , "Tennis serve that the receiver can't reach" , "Winning serve; hole in one" .)