English Idiom of the Day – Win by a Nose
To 'win by a nose' means to win by a very small amount.
Example: I ran the fastest race I could, but I only won by a nose.
Sally won the race, but she only won by a nose
Did you know...? This idiom comes from horseracing, where from about 1900 on it referred to a finish so close that only the tip of the horse's nose reached the finish ahead of the second horse.
There is a similar idiom with the same meaning - to 'win by a whisker'.