Score with little time left before close of play (6)
I believe the answer is:
Here is my best explanation:
'score' is the definition.
('twenty' can be a synonym of 'score')
'with little time left before close of play' is the subsidiary indication.
'with' is a charade indicator (letters next to each other).
'little time' becomes 't'.
'left' becomes 'went' (I've seen this before).
'before close of play' becomes 'y' (I've seen this in other clues).
't' put next to 'went' is 'twent'.
(Other definitions for twenty that I've seen before include "Number", "This twice denotes normal vision", "John B Keane wrote about many young men of this age", "No longer a teenager", "Hundredweights to a ton", "No. between 5 and 1 on dartboard", "made by Q on a light blue square", "A Score", "Cardinal" and "Score, XX".)