PINEHURST, N.C. -- Ludvig Aberg and his machine-like game are proving to be a perfect fit for Pinehurst No. 2. The Swedish star methodically worked his way to a 1-under 69 on Friday and a 1-shot lead going into the weekend of his U.S. Open debut.

Aberg wasn't flawless -- he did miss two fairways on a punishing course -- but he avoided big blunders and big numbers on a day of oppressive heat in the North Carolina sand hills that derailed so many others.

He was at 5-under 135 and led by 1 stroke over Bryson DeChambeau (69), Patrick Cantlay (71) and Thomas Detry (67) going into a weekend that won't include Tiger Woods and barely includes Masters champion Scottie Scheffler.

Pinehurst No. 2 is tough enough without a heat index that pushed toward 100 degrees (38 Celsius) at the peak of the afternoon, and with just enough wind to cause doubt.

That's just how the 24-year-old Swede likes it.

"It's not an easy golf course to play," Aberg said. "But I felt like we stayed very disciplined, stayed very patient and tried to hit it to our targets all the time. We said beforehand, 'See how many good shots we can hit today and see where that ends up.'"

He wound up with another chance on a big stage. Just over a year after he graduated from Texas Tech, Aberg already is No. 6 in the world, has won on both sides of the Atlantic, played in a Ryder Cup and was runner-up in the Masters.

"It's the first time I've ever played with him. The guy is like a machine from what I saw," Tony Finau said after a 69 left him only 2 shots behind. "I obviously am focused on what I'm doing and playing my game, but he hit a lot of fairways and a lot of greens.

"He sure makes it look pretty easy."

DeChambeau relied more on his putter than his power and will be in the final group with Aberg. It was the ninth time in the last 10 rounds in the majors that DeChambeau has been among the top 10 on the leaderboard.

DeChambeau was all over the place -- three times following a a birdie with a bogey, saving plenty of pars with putts in the 5-foot range and finishing on a high note with a wedge into tap-in range for birdie on the 18th.

"All in all, was very happy with how I stayed patient, gave myself good opportunities when they mattered, and I made a lot of clutch putts coming in," he said.

He finished early, just as the sun was starting to bake out the course and its sandy landscape. So did Detry, the 31-year-old Belgian who was the first player to reach 6 under until dropping two shots over his last four holes.

Cantlay and Matthieu Pavon tried to keep pace with Aberg. Cantlay was flawless through seven holes until he went over the back of rock-hard eighth green, went back over the other wide, took two shots to reach the green and had to make a 12-footer for double bogey.

He dropped back again with tee shots into the scruffy dunes with native grasses, leading to bogey on the 16th and keeping him from a birdie chance coming in.

But for a player who has been out of the conversation most of the year, Cantlay suddenly is looking as good as ever against such a strong test of golf. That much he was expecting.

"I think this golf course is going to play very challenging over the weekend, especially with the forecast that we have. It's inevitable there's going to be some mistakes made, but that's just part of playing a U.S. Open," Cantlay said.

"The line is very fine around here," he said. "Just a yard one way or the other can be a dramatic difference."

The temperature is expected to get even hotter, the course even tougher. In the previous three U.S. Opens at Pinehurst No. 2, a total of four players finished under par. There were 15 players under par going into the weekend.

That included Rory McIlroy, who chipped in for par on the 17th hole and got away with a balky putter for a round of 72 that left him two shots out of the lead. Former Masters champion Hideki Matsuyama had the best score of the second round at 66 and was three behind.

PGA champion Xander Schauffele started with two straight bogeys, had a double bogey and still managed a 69 to get within four shots.

All of them are chasing Aberg. No one has won the U.S. Open in his first try since 20-year-old Francis Ouimet in 1913 at The Country Club. Aberg is hardly a newcomer to this kind of stage.

The Associated Press contributed to this report.