Help one to get top in sort of contest (8)
I believe the answer is:
handicap
'sort of contest' is the definition.
(contest in which players are handicapped)
'help one to get top' is the wordplay.
'help' becomes 'hand' (hand is a kind of help).
'one' becomes 'i' (Roman numeral).
'to get' says to put letters next to each other.
'top' becomes 'cap' (synonyms).
'hand'+'i'+'cap'='HANDICAP'
'in' is the link.
(Other definitions for handicap that I've seen before include "millstone" , "liability" , "Disadvantage imposed on competitor to equalise chances" , "race" , "Block" .)