Tennis ace Sampras (4)
I believe the answer is:
pete
'tennis ace sampras' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pete that I've seen before include "-- Sampras, tennis ace" , "Small 14 [PETER JONES]" , "- Sampras, tennis star" , "For his sake" , "- Doherty, Babyshambles singer" .)