McNeill, whose only victory on the PGA Tour came five years ago at the Frys.com Open, birdied the final two holes at the Trump International Golf Club for a three-day total of 13-under 203.
Henrik Stenson and Kevin Stadler shared second place at 204 while Matt Jones, who held a three-shot advantage at the start of the round, settled for a 72 and stood alone in fourth at 205. Stenson equaled the day's low round of 65 while Stadler had a 69.
Daniel Summerhays and Ryo Ishikawa were tied for fifth at 206.
McNeill eagled the par-5 fifth to get his round started and posted the 67 despite suffering back-to-back bogeys on the front nine. His best finish this season has been a tie for 19th at the Sony Open in Honolulu. McNeill missed the cut in two of his three previous starts.