Even bits of watches provide good service (3)
I believe the answer is:
ace
'good service' is the definition.
(a good serve in tennis)
'even bits of watches' is the wordplay.
'even bits of' indicates alternate letters.
The alternating letters of 'watches' are 'ACE'.
'provide' acts as a link.
(Other definitions for ace that I've seen before include "Playing card with single spot" , "One or 11 in cards" , "Great" , "Expert (sl.)" , "first-class" .)