Despite a three-putt bogey at No. 18, the Naples, Fla. native closed with a 5-under-par 67 to finish 23-under 264.
"It is nice to fulfill a dream and hopefully there are more to come," said McNeill after he earned $720,000 for the title. "I've been grinding throughout the year, trying to look for some game (but) I've felt very comfortable with what I've been doing over the past few days, so I just went with it."
D.J. Trahan (66) was the runner-up at 19-under 268.
Megyn Kelly: Santa Claus and Jesus are both white men
Video of Victoria’s Secret models trying to 'twerk' hits Instagram