Be at a race to conclusion (6)
I believe the answer is:
attend
'be at' is the definition.
(I've seen this before)
'a race to conclusion' is the wordplay.
'race' becomes 'tt'.
'to conclusion' becomes 'end' (something's conclusion is its end).
'a'+'tt'+'end'='ATTEND'
(Other definitions for attend that I've seen before include "notice" , "Be present at, or accompany" , "Be there ? pay attention" , "put in an appearance" , "Take part in" .)