win by a nose
Also, win by a whisker. Just barely succeed, as in Sally's political cartoon came in first in the contest, but I heard that she won by a nose. This term comes from horseracing, where from about 1900 on it referred to a finish so close that only a portion of the horse's nose reached the finish ahead of the second horse. A whisker
that is, a hairis a narrower margin yet. [Second half of 1900s]