Was winning (3)
I believe the answer is:
led
'was winning' is the definition.
(to lead can mean to be winning a game)
This is all the clue.
(Other definitions for led that I've seen before include "Light-emitting diode (abbr.)" , "Came first" , "Emitter of light" , "Went first to show the way" , "Shown the way" .)