Sports talk radio is often the scene of atrocious grammar crimes. I just heard the same mistake, made by two different people, within the span of 30 minutes.
Case 1: "Oakmont is the toughest course on the tour, if not one of the top five."
Case 2: "Robert Horry is probably public enemy #1 in Phoenix, if not among the top few."
You see the problem? They're getting it backwards. Here are the corrected versions:
Case 1: "Oakmont is one of the five toughest courses on the tour, if not THE toughest course."
Case 2: "Robert Horry is among the top few public enemies in Phoenix, if not public enemy #1."
You get it? You need to go from wider to narrower, not vice versa.