LA QUINTA, Calif. – Patrick Cantlay’s magical weekend fell just short of an unforgettable ending.

Cantlay shattered the course record by two strokes with an 11-under 61 at PGA West’s Pete Dye Stadium Course. After making the cut on the number at 4-under, he exploded for 20 birdies over his weekend 36 holes, tying the best score in relation to par in the final two rounds of a 72-hole event on the PGA Tour (18-under).

It took an equally flawless round of 64 from 54-hole leader Si Woo Kim to edge him out for the trophy at the American Express.

“I did everything I could,” Cantlay said. “He just played unbelievable too.”

The American Express: Leaderboard | Winner’s bag | Prize money

Cantlay, 28, is beginning to develop a reputation for going low on the weekend. At the 2019 Masters, he also made the cut on the number and shot 64-68 to take the lead after an eagle at 15 before finishing T-9. In late October, he poured in nine birdies to rally from three strokes back and win the Zozo Championship. This time, Cantlay started Sunday four strokes back.

“I put myself so behind the 8-ball making the cut just on the number,” he said.

On Moving Day, he shot 65, which would’ve been even better had he not hit a shot out of bounds at No. 8, his 17th hole of the day. Knowing he needed to go low on Sunday, Cantlay carded a career-high 11 birdies. The top-ranked player in the field at World No. 10, Cantlay capped off an unforgettable round with a 38-foot birdie putt at the last.

“It kept building and building and today I felt like I could make everything and I made a lot of them,” he said of the 151 feet, 10 inches of putts he holed on Sunday, his most feet of putts made in a round of his Tour career.

“He played video game golf,” said Cantlay’s swing instructor Jamie Mulligan.

On a sun-splashed day lacking the forecasted wind, Cantlay took advantage, one of three players to tour the first nine in 6-under 30. It included the only dicey moment of the day as he nearly dropped a shot at No. 7 when he tugged his drive and had to pitch out.

But he rescued par with a 9-foot par putt and dodged every landmine on the Dye layout. At the par-3 13th, with water left and the flag tucked dangerously close to it, he drew a beautiful tee shot that caught the slope and stopped 5 feet away. He missed a 6-foot birdie putt at No. 14, shaking his head in disappointment, but bounced back with a 20-foot birdie putt one hole later. Shortsided and with a downhill lie, he hit a delicate pitch from 30 yards to 5 feet for another birdie at the par-5 16th that playing competitor Garry Woodland applauded.

When Cantlay sank his 38-foot birdie putt at 18, he walked over to his caddie Matt Minister and said, “That’s as good as I can play.”

It was a weekend for the record books, but not enough to lift a trophy.