Brooks Koepka beat Talor Gooch in a play-off to win LIV Jeddah, but the runner-up claimed £14.8m as the season's overall champion.
Five-time major winner Koepka, 33, hit a two-under 68 to finish on 14 under par after three rounds at the Royal Greens course in Saudi Arabia.
He was reeled in by fellow American Gooch's 62, but won the play-off with a birdie at the second extra hole.
Koepka, who was third in the overall standings, earned £3.3m for the win.
This year's PGA champion also earned the same again for his finish in the season's standings.
Gooch, 31, had been going for a fourth tournament win of the season after back-to-back victories in Adelaide and Singapore in April and the Andalusia event at Valderrama in July.
But by the time he had drawn level with Koepka to force the play-off, his multi-million-dollar victory in the overall standings had already been confirmed.
Australia's 2022 Open champion Cameron Smith, 30, was second overall for the season.
The LIV Golf season finishes with the Team Championship in Miami from 20 to 22 October.
