Runner-up in close race? (5)
I believe the answer is:
loser
'runner-up' is the definition.
'in close race?' is the wordplay.
'in' indicates a hidden word.
'LOSER' is hidden in the letters of 'close race'.
(Other definitions for loser that I've seen before include "Defeated person" , "Unsuccessful type" , "One who is (always) unsuccessful" , "one plays without success" , "No-hoper" .)