Taking someone on and winning (8)
I believe the answer is:
engaging
'winning' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for engaging that I've seen before include "Taking into employment" , "Attractive or charming - getting married?" , "Attractive; employing" , "embarking on military action" , "Interesting" .)