The South African posted a bogey-free, 6-under-par 64 to take the first-round lead at the Open Championship at Royal St. George’s in Sandwich, England, one shot better than Jordan Spieth and Brian Harman.

Oosthuizen’s only major victory came at the 2010 Open at St. Andrews, but he has six runner-up finishes in majors — including this year’s PGA Championship and U.S. Open.

“It depends if you lost it or someone else beat you,” Oosthuizen said of getting past near-misses. “I think in both of those I was beaten by better golf at the end there … I tried to take a few days and just try and forget about it and see if I can get myself ready for the next one.”

The trio of Harman, Canadian Mackenzie Hughes and South African Dylan Frittelli, grouped together for the first two rounds, all went low. Harman birdied No. 18 to tie Spieth at 5-under 65 and Hughes and Frittelli each shot 4-under 66. Webb Simpson, Frenchman Benjamin Hebert and 48-year-old Stewart Cink also joined a tie for fourth at 4 under.

Oosthuizen landed his tee shot on the par-3 16th inside eight feet of the pin to set up his sixth birdie of the day. After warming up with seven pars to start his round, he had a three-birdie run on Nos. 8-10 and later tied Spieth at 5 under with two more on Nos. 13 and 14.

“(It was) probably in my mind the perfect round I could have played,” said Oosthuizen. “I didn’t make many mistakes. When I had good opportunities for birdie, I made the putts.”

Following an early bogey, Spieth’s long putt from the fringe on No. 5 kicked off a string of four straight birdies as he staked out his spot near the top of the leaderboard. He added two more on the back nine.

The 2017 Open champion, Spieth entered the week leading all players in Open Championship scoring average since 2015 (69.6), according to the PGA Tour. His 65 marked his 13th Open round in the 60s in that span, which leads the pack as well.

“Here I feel, for the first time since (2017), I’m at least coming in with a bit of form, a bit of confidence and really in my start lines off the tee,” Spieth said. “I felt like I drove the ball good enough today to be able shoot a really good score, and I’d like to improve.”

A 10-way tie at 3-under 67 featured world No. 4 Collin Morikawa and five Englishmen: Justin Rose, Tommy Fleetwood, Andy Sullivan, Danny Willett and Jack Senior.

Brandt Snedeker came inches away from a hole-in-one on No. 16, then holed out from the fairway for eagle the very next hole on his way to a 2-under 68. World No. 1 Dustin Johnson, Spain’s Sergio Garcia and Norway’s Viktor Hovland also joined a large tie at 2 under, while four-time major winner Brooks Koepka opened with a 1-under 69.

Rory McIlroy bogeyed three straight starting at the fifth, where he lipped out a short par putt. A tee shot into the bunker on the par-3 sixth did him in, and he sprayed shots left and right on No. 7 before ending the skid with a birdie.

Despite his early struggles, the Northern Ireland star sank his fourth birdie on No. 18 to finish at even-par 70.

Bryson DeChambeau, who posted a 1-over 71, only hit one fairway in regulation over his first 12 holes. His scrambling kept him afloat, and starting at No. 12 he managed three straight birdies, thanks in part to his decision to hit iron off the tee at the par-5 14th.

“If I can hit it down the middle of the fairway, that’s great, but with the driver right now, the driver sucks,” DeChambeau said. “It’s not a good (club) face for me and we’re still trying to figure out how to make it good on the mis-hits.”

Defending champion Shane Lowry and world No. 2 Jon Rahm, Oosthuizen’s playing partners, also shot 1-over 71. Phil Mickelson took himself out of contention with a 10-over 80.

Following the second round, the top 70 players including ties will qualify for the weekend.