Steal the limelight from the coach to London (7)
I believe the answer is:
Here is my best explanation:
This clue is a double definition.
'steal the limelight' is the first definition.
'the coach to london' is the second definition.
(stagecoach in direction of major city or capital)
'from' is the link.
(Other definitions for upstage that I've seen before include "Divert attention from someone towards yourself", "Divert attention from another as actor might in play", "Take attention from (another actor)", "Pugs eat (anag.)", "Try to attract attention", "Direct attention away from someone on to oneself", "Take the limelight from", "aloof", "Outshine" and "steal the show".)