Run and run on one (4)
I believe the answer is:
race
'run' is the definition.
(I've seen this before)
'run on one' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'on' says to put letters next to each other.
'one' becomes 'ace' ('ace' can be a synonym of 'one').
'r'+'ace'='RACE'
'and' is the link.
(Other definitions for race that I've seen before include "Run fast" , "Contest; nation" , "Contest; zoom" , "People - sprint - competition" , "Run; nation" .)