Twin winning share (6,2)
I believe the answer is:
double up
'share' is the definition.
(doubling up is a kind of sharing)
'twin winning' is the wordplay.
'twin' becomes 'double' (I've seen this before**).
'winning' becomes 'up' (I've seen this in other clues).
'double'+'up'='DOUBLE UP'
(Other definitions for double up that I've seen before include "Bend forward in pain or laughter" , "Lean over as in laughter or pain - twice?" , "Take another gamble" , "Bend in two (with laughter or pain)" , "React to punch in gut" .)