Wizard, one in a suit (3)
I believe the answer is:
ace
I believe this clue is a double definition.
'wizard' is the first definition.
('ace' can be a synonym of 'wizard')
'one in a suit' is the second definition.
(I've seen this before)
(Other definitions for ace that I've seen before include "hotshot" , "winner in court" , "single > club > champion" , "Playing card - expert" , "Good; service; card" .)