34-year-old Amy Yang birdied her last two holes to win the CME Group Tour Championship — and $2 million (€1.83m) — with a 6-under 66.
The South Korean golfer dropped her face in her hands before being doused in enough champagne that she needed to towel off before signing her card.
"Never give up," said Yang, the oldest winner on the LPGA Tour this season, who said an elbow injury had her thinking her career was over not too long ago. "Just have a dream and work hard."
"I thought my career would be over very soon and I just didn't see myself winning again. But, you know, I tried to stay patient and positive about my future and I'm just so happy."
At one point Yang was three shots behind but made an eagle on the 13th and birdied the 17th and 18th to finish in style.
This is her first American LPGA victory, following four in Asia.
Alison Lee made four birdies over her last four holes for second place — the same finish she achieved in her previous two LPGA events, which she admitted has been painful.
"This is my third time getting second place now in the last three LPGA events, so it's definitely tough because it's hard. It's tough to put yourself in contention and get yourself in the final group on Sunday. Been really proud of my performance over the last month, I can't complain there. Obviously the only complaint is I wish I won one of those three."
Nasa Hataoka — who had been tied with Yang and Lee going into the final three — finished in third, Lilia Vu in fourth, and Atthaya Thitikul in fifth.
Vu was honoured as Player of the Year after four victories this season, including two majors, while Thitikul won the Vare trophy for low scoring average.