Knock over the firelighter (5)
I believe the answer is:
spill
This clue is a double definition.
'knock over' is the first definition.
(I've seen this in another clue)
'firelighter' is the second definition.
(I've seen this before)
'the' is the link.
(Other definitions for spill that I've seen before include "Cause liquid to flow from a container" , "Thin piece of wood used to light a fire" , "Thin piece of wood or rolled paper to light a fire" , "Let fall accidentally - lighter" , "Oil tanker mishap?" .)