Scottie Scheffler claims victory at the American Express, securing his 20th title on the PGA Tour.

LA QUINTA, Calif. — Scottie Scheffler commenced his season as if nothing had altered, recording four birdies in a six-hole span on Sunday to surge past 18-year-old Blades Brown and the rest of the competitors. He finished with a 6-under 66, securing a four-shot victory at The American Express.

Scheffler achieved his 20th win on the PGA Tour — all within the last four years — which grants him a lifetime membership. More reflective of his supremacy in the sport is the fact that he has won nine of those 20 tournaments by margins of four shots or greater.

With 20 victories and four major championships before reaching 30, Scheffler joins Jack Nicklaus and Tiger Woods as the only players to accomplish this feat.

“Pretty wild,” Scheffler remarked. “It’s been a great start to my career. It’s been special. I try not to dwell on that too much. I was just focused on doing what I needed to be prepared.”

The world’s top-ranked player shared the spotlight with Brown, who completed high school just two weeks prior and participated in a Korn Ferry Tour event in the Bahamas that concluded Wednesday. He is the first player to compete in eight consecutive days of PGA Tour-sanctioned events.

Whether fatigue set in or the moment overwhelmed him — as he aimed to become the youngest PGA Tour winner in 95 years — his challenge ended swiftly.

Brown was one shot behind 54-hole leader Si Woo Kim and one shot ahead of Scheffler as they approached the tee at the par-3 fourth on the Stadium Course at PGA West. Five holes later, both Brown and Kim found themselves five shots back, while Scheffler was accelerating his performance.

Scheffler struck a delicate 8-iron to 2 feet on the fourth for a birdie and found the fairway on the par-5 fifth. Brown’s tee shot found the water, necessitating a drop in front of the tee boxes — he nearly dropped into the dormant Bermuda rough instead of the teeing area — and then hit a poor wedge that resulted in a double bogey.

Brown went 11 holes without a birdie and suffered two late bogeys, finishing with a 74. He dropped from a tie for second to a tie for 18th, losing his chance to compete at Torrey Pines next week.

“Eight rounds may sound like a lot, but I was having a lot of fun,” he stated. “You’re telling me I get to play in a PGA Tour event and compete with Scottie Scheffler and witness him win, that was incredible.

“I have some areas I need to refine, and hopefully we can achieve what Scottie’s doing.”

Scheffler has claimed four of his last six PGA Tour starts and seven of his last 13. He has recorded top 10 finishes in 16 consecutive tour starts, extending the longest streak by any player since 1970.

Jason Day concluded with a 64, moving him up 18 positions to a runner-up finish, alongside Ryan Gerard (65), Matt McCarty (68), and Andrew Putnam (68).

Kim, who frequently plays with Scheffler at Royal Oaks in Dallas, also encountered difficulties on one hole. He was two shots behind on the par-5 eighth when he took two attempts to escape a greenside bunker, chipped well, and made a double bogey. He missed a 3-foot par putt on the subsequent hole. Kim recovered with three birdies on the back nine to finish with a 72 and tie for sixth.

Scheffler maintained his momentum. He nearly holed a chip right of the par-5 11th for a tap-in birdie. He hit a wedge to 2 feet on the next hole for another birdie and headed to the 13th tee with a four-shot advantage.

His only significant error occurred when it was inconsequential, a tee shot into the water on the par-3 17th known as “Alcatraz,” and by that point, Scheffler had ample leeway. He took a double bogey, but the margin remained substantial against the strongest field The American Express has seen in decades.

Scheffler will take a week off before concluding the West Coast swing with three consecutive events, beginning with the Phoenix Open, where this remarkable streak initiated four years ago. He secured his first PGA Tour title in a playoff. It hasn’t been that close recently.

Information from ESPN Research and The Associated Press was used in this report.