Opportunity to refuel in worst place - and best (7)

I believe the answer is:
pitstop
'opportunity to refuel' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'worst place and best' is the wordplay.
I cannot quite understand how this works, but
'worst' could be 'pits' (I've seen this in another clue) and 'pits' is found in the answer.
'place' could be 'top' (top is a kind of place) and 'top' is located in the answer.
No letters remain.
This explanation may well be incorrect...
'in' is the link.
Can you help me to learn more?
(Other definitions for pitstop that I've seen before include "Racing driver's halt" , "Race servicing break" , "Car race service break" , "Time taken in motor racing to fit a 3, for instance" , "Race refuelling break" .)
