Manage to keep going (5,2)
I believe the answer is:
carry on
I believe this clue is a double definition.
'manage' is the first definition.
(carrying on is a kind of managing)
'keep going' is the second definition.
(I've seen this before)
'to' is the link.
(Other definitions for carry on that I've seen before include "Have an affair - cause a fuss - continue" , "Keep going!" , "film series" , "song and dance" , "hand luggage on American Airlines?" .)