Finished second even without regulars to supervise (7)
I believe the answer is:
oversee
'supervise' is the definition.
('oversee' can be a synonym of 'supervise')
'finished second even without regulars' is the wordplay.
'finished' becomes 'over' ('over' can be similar in meaning to 'finished').
'second' becomes 's' (common abbreviation).
'without regulars' means one should take alternating letters (letters must be removed at regular intervals).
The alternating letters of 'even' are 'ee'.
'over'+'s'+'ee'='OVERSEE'
'to' is the link.
(Other definitions for oversee that I've seen before include "Administer" , "Disregard" , "Superintend, manage" , "Direct" , "Keep an eye on like foreman" .)