Bet sporting contest’s captivating Brazil’s wingers (6)
I believe the answer is:
gamble
'bet' is the definition.
(I know that bet can be written as gamble)
'sporting contest's captivating brazil's wingers' is the wordplay.
'sporting' means one lot of letters goes inside another (inserted letters wear or 'sport' others).
'contest' becomes 'game' (game is a kind of contest).
'captivating brazil's wingers' becomes 'bl' (I can't justify this - if you can you should give a lot more credence to this answer).
'game' placed around 'bl' is 'GAMBLE'.
(Other definitions for gamble that I've seen before include "punt" , "Bet -- Procter's partner" , "Make a bet" , "Risky enterprise" , "Take risks" .)