The girl has Silas beaten by one point (6)
I believe the answer is:
lassie
'the girl' is the definition.
(lassie is a kind of girl)
'silas beaten by one point' is the wordplay.
'beaten' indicates an anagram.
'by' is a charade indicator (letters next to each other).
'one point' becomes 'e' (E is an example**).
'silas' anagrammed gives 'lassi'.
'lassi'+'e'='LASSIE'
'has' acts as a link.
(Other definitions for lassie that I've seen before include "Movie role for several dog stars" , "Screen mutt - Scottish girl" , "TV series/film dog" , "Collie featuring in many films" , "Young Scottish female" .)