After a terrible start score with some difficulty (2,1,7)
I believe the answer is:
at a stretch
'with some difficulty' is the definition.
(at a stretch means in difficult circumstances)
'after a terrible start score' is the wordplay.
'after' is a charade indicator (letters next to each other).
'terrible' indicates an anagram.
'score' becomes 'etch' (etch can mean to score or carve into something).
'start' is an anagram of 'tastr'.
'a' put next to 'tastr' is 'atastr'.
'atastr'+'etch'='AT A STRETCH'
(Other definitions for at a stretch that I've seen before include "With difficulty; without interruption" , "With much effort" , "in one continuous period" , "Running, possibly" .)