In front by a winning distance (5)

I believe the answer is:
ahead
'in front' is the definition.
(synonyms)
'by a winning distance' is the wordplay.
'by' says to put letters next to each other.
'winning distance' becomes 'head' (I can't explain this - if you can you should believe this answer much more).
'a' put next to 'head' is 'AHEAD'.
Can you help me to learn more?
(Other definitions for ahead that I've seen before include "What's down the road" , "Forwards" , "In front as in race" , "In the future" , "In the leading position" .)
