Pits against fire starters (7)
I believe the answer is:
matches
'pits' is the definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Maybe you can see a link between them that I can't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for matches that I've seen before include "Sporting occasions" , "Contests or partnerships of equals" , "Shares a colour with" , "ties" , "Picks out for union potential" .)