Race turns out to be a downhill race (6,3)
I believe the answer is:
cresta run
'be a downhill race' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'race turns out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'race'+'turns'='raceturns'
'raceturns' with letters rearranged gives 'CRESTA RUN'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for cresta run that I've seen before include "tobogganing slope" , "Frozen channel" , "Swiss skeleton toboggan track" .)