Opportunity to split (5)
I believe the answer is:
break
I believe this clue is a double definition.
'opportunity' is the first definition.
(I have seen 'Better opportunity' mean 'break' so perhaps 'opportunity' could also mean 'break')
'split' is the second definition.
(I know that split can be written as break)
'to' acts as a link.
(Other definitions for break that I've seen before include "Baker (anag.)" , "accumulation of points" , "Shatter; respite" , "Better opportunity" , "Fracture; holiday" .)