Rory McIlroy had his first bogey-free round in a major since his last time winning one 10 years ago, a 5-under 65 that gave him a share of the lead with nemesis Patrick Cantlay.
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McIlroy had one of two clean cards, a rarity for Pinehurst No. 2. He capped off his round with a 20-foot birdie putt on the 18th hole, where he was taking his fourth step toward the cup when it dropped and he waved to the crowd in the double-deck grandstands.
That was about the only thing that didn't go as planned for McIlroy.
"I wasn't showing off. I thought I left it short," McIlroy said. "But it got up there, it was nice, and a great way to finish. The way I played today, the way I hit the ball, the way I managed myself, I felt like that score was pretty deserved."
Cantlay played in the morning beneath a full sun, holing out from a bunker for birdie on his second hole and making a pair of birdie putts in the 20-foot range in an otherwise tidy round marred by only one bogey.
McIlroy was in control from the start, hitting 6-iron to 7 feet at the 528-yard fourth hole - the toughest par 4 on the course - for birdie, and then chipping in from the front of the green on the next hole.
He has the advantage of towering iron shots that land softly, and they were usually pin-high and away from the domed edges of the Donald Ross greens that cause so much trouble.
McIlroy has won majors the last three times he has started with a bogey-free round - at Hoylake in the 2014 British Open, at Kiawah Island in the 2012 PGA Championship, and at Congressional in the 2011 U.S. Open.
"Getting off to a good start is important to try to keep yourself up there, because you have to give yourself as big of a cushion as possible, knowing what is lurking around the corner," McIlroy said.
Seemingly unflappable and definitely in contention, Ludvig Aberg's U.S. Open debut couldn't have gone much better.
And if the 24-year-old Swede can maintain his ball-striking ability over the next 54 holes, he has a chance to become the first rookie to win the tournament in more than a century.
Aberg fought off some pre-round nerves Thursday and hit all 14 fairways and 16 of 18 greens at Pinehurst's difficult No. 2 course to shoot 4-under 66, leaving the budding star in contention for his first major championship.
"I'll absolutely take it," Ludvig said. "I'm very, very pleased, obviously. I wouldn't want to have to do it again."
Not since Francis Ouimet beat Harry Vardon and Ted Ray in an 18-hole playoff in 1913 has a first-time participant won the U.S. Open.
Aberg's success doesn't come as a huge surprise. He finished second at the Masters last month and is ranked sixth in the world.
Tony Finau said he'd never played with Aberg before and walked away impressed.
"Yeah, he's a strike show," said Finau, who shot 67. "He's far from a rookie. I mean, he's not even your average first guy playing in a major championship. He's been on some of the biggest stages already and shown he's going to be a world-class player. It was a joy to watch."
Aberg averaged 321 yards off the tee, outpacing the remainder of the field. But it was his accuracy that stood out in Round 1.
Tiger Woods teed off Thursday morning. It's the first time Woods has teed it up since a disappointing showing at the PGA Championship in Louisville at Valhalla.
After a good start, Woods had five bogeys in a seven-hole stretch around the turn for a 74, his 12th consecutive round in the majors without breaking par.
World No. 1 Scottie Scheffler was paired with fan favorite McIlroy and PGA Champion Xander Schauffele.
Clearly the favorite, Scheffler tries to focus on the US Open
Scheffler spent his opening round at the U.S. Open in a strange situation.
He was over par.
The world's top-ranked player had played 21 holes all season when he was over par for a tournament, yet that's where Scheffler found himself after a bogey at the par-4 third on Thursday. He spent the rest of the day over par, too, balancing a pair of birdies with two more bogeys for a 1-over 71 that left him in contention but with ground to make up.
His playing partner, McIlroy, shot a bogey-free 65 that put him in a tie with Patrick Cantlay atop the leaderboard. Schauffele, finished at even-par.
"Every week we play, he seems to build a bigger lead, and somehow make the mountain even taller for all of us to climb," Schauffele said earlier in the week. "That's all he's been doing, and hats off to him for being so consistent."
Scheffler wasn't far off his usual brilliance at Pinehurst on Thursday.
On the third, Scheffler's tee shot barely trickled into the native grass, and his approach looked good until it bounced off the contoured green and into a bunker. He missed his par putt so badly that he started walking the moment he hit it.
At the par-3 sixth, Scheffler managed to get his tee shot onto the massive green. But his lag putt was poor, leaving about 18 feet for par, and that miss dropped him to 2 over for only the second time at any point in a tournament this year.
Scheffler got a shot back at the seventh when he hit his approach from 164 yards to 12 feet and made birdie. But he also missed a 12-footer for birdie at the 10th, and one from a bit longer at the 11th, that could have provided him some momentum.
His biggest blunder -- only one, really -- came at the par-4 16th when Scheffler's tee shot went so far left that it rattled among the fans like a pinball before settling into the pine straw. He caught a break when a tower was in his way, giving him a free drop and a clean look at the green, but his approach wound up in a collection area and he made another bogey.
Scheffler finished strong, though, on a day where perseverance was rewarded. After watching McIlroy and Schauffele hit nice shots into the long par-3 17th, he stuck his own inside them. And with a confident stroke, Scheffler rolled that 12-footer dead-center of the cup for his final birdie of the day. He added a tap-in par at the 18th, and after signing his card, headed right to the practice range for some early evening work.
The last time the U.S. Open was held at Pinehurst back in 2014 Martin Kaymer won convincingly over Rickie Fowler.
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Tiger Woods was among the big-name golfers who did not make the cut Friday at Pinehurst No. 2. Kate Rogerson has the latest
The Associated Press contributed.