Si Woo Kim clinched his third career PGA Tour title with a narrow one-stroke victory at The American Express on the Stadium Course in California.
Kim, 25, carded a stunning final-round 8-under 64 to finish on 23-under par and one shot clear of Patrick Cantlay, who fired an incredible course-record 11-under 61.
Starting the day in a three-way tie for the lead, the South Korean rolled in four birdies in the space of five holes from the 4th hole, before adding consecutive birdies at 10 and 11 to move into the outright lead.
Cantlay - playing six groups ahead of Kim - set the clubhouse target of 22-under par following a magical round of 61 that comprised of 11 birdies, including a 37-foot bomb at the final hole.
That left Kim trailing by one stroke as he stood on the tee at the par-5 16th.
Kim kept his composure and two-putted for birdie at 16 to join Cantlay at the top on 22-under par, before he then drained an 18-footer for birdie at the short but testing par-3 17th to nose back in front.
He then showed great course management down the par-4 18th when finding the fairway with a 3-wood, before sending a short iron into the heart of the green and two-putting for par and the victory.
"This win means a lot to me," said Kim. "I feel like I've got a lot more confidence after this win now."
Australia's Cameron Davis matched Kim's round of 64 to finish solo third on 20-under par.
The victory marks Kim's third on the PGA Tour and his first since landing the flagship Players Championship at TPC Sawgrass by three strokes in 2017. Kim won his first title the 2016 Wyndham Championship by five strokes.
Tony Finau started the day in a tie for the lead with Kim, but his wait for a second PGA Tour title since picking up his maiden win at the 2016 Puerto Rico Open continues.
Finau opened his round with consecutive birdies at the first two holes, and then added another two birdies at the 8th and 10th to remain well in contention for the title.
However, he was left to rue finding the water with his second shot into the par-5 11th and he then compounded that mistake when missing a two-foot putt for par. He then followed that bogey with another at the 14th to fall out the running for the win.
To his credit, he went on to birdie the 15th and 18th to sign for a 68 and finish solo fourth on 19-under par, but it now marks an incredible 35th top-10 finish for the affable American since his first and only victory on the PGA Tour.