Martin Laird clinched his maiden PGA Tour win after a three-way play-off at the Justin Timberlake Shriners Hospitals Children Open.
The 26-year-old, who now receives a two-year tour exemption, carded a final round 68 in Las Vegas to finish on 19-under-par alongside George McNeill and Chad Campbell.
Campbell was eliminated at the second play-off hole before a bogey by O'Neill at the next gave Laird two putts for the title.
The victory makes Laird the first Scot since Sandy Lyle at the Masters in 1988 to win a top tier PGA Tour event and moves him up to 62nd on the US money list.
"The most nervous I was was the first few holes starting out, and then coming in there I was amazed how calm I was coming down the stretch," said the Glaswegian after picking up a winner's cheque for £462,000.
"When I got into the play-off I was surprised; I kind of chilled out a little. I was pretty nervous the last two or three holes in regulation, and once I got there in the play-off I kind of relaxed a little more."