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