A touch below par, ultimately in fierce competition (3,4)
I believe the answer is:
rat race
'fierce competition' is the definition.
'a touch below par ultimately' is the wordplay.
'touch' becomes 'trace' ('trace' can be a synonym of 'touch'**).
'below' is a charade indicator (letters next to each other).
'ultimately' indicates one should take the final letters.
The final letter of 'par' is 'r'.
'a'+'trace'='atrace'
'atrace' put after 'r' is 'RAT RACE'.
'in' acts as a link.
(Other definitions for rat race that I've seen before include "Competitive routine with no time to relax" , "Fiercely competitive struggle in business" , "The daily grind" , "Competitive daily existence" , "struggle for position" .)