Owing student small matches (5)
I believe the answer is:
duels
'matches' is the definition.
The definition and answer can be both related to competing as well as being verbs in their -s form.
Perhaps you can see a link between them that I can't see?
'owing student small' is the wordplay.
'owing' becomes 'due' (similar in meaning).
'student' becomes 'l' (as in L-plates for learner drivers).
'small' becomes 's' (abbreviation - e.g. clothes size).
'due'+'l'+'s'='DUELS'
Can you help me to learn more?
(Other definitions for duels that I've seen before include "Clashes" , "Affairs of honour" .)