PINEHURST, N.C. -- Rory McIlroy is again knocking at the door.

A day that began with Patrick Cantlay posting a first-round 65 to take the early lead at the U.S. Open ended with an exclamation point: McIlroy walking in a 20-foot birdie putt on the 18th hole that punctuated a bogey-free spin around Pinehurst No. 2 and gave him a share of the lead.

"I thought I left it short," McIlroy said with a smile. "That's why I walked after it."

Though unintentional, the early walk-in would have been fitting of the round McIlroy had. It wasn't that he overpowered the golf course or that he made every putt he saw. Instead, he played with discipline and was confident in the quality of his game.

"It was a really controlled round of golf," McIlroy said.

McIlroy hit 15 of 18 greens, and the three that he did not hit he was able to get up-and-down for par with ease. After spraying a drive right on the par-5 fifth hole and misjudging the layup and the approach, the chip-in for birdie set the tone for the round. McIlroy had a stretch of four straight pars on the front nine and five straight pars on the back before making a birdie on the par-5 16th hole and the putt on 18.

"I could have got a little impatient," said McIlroy, a four-time major winner. "But I felt like my patience was rewarded there with birdies on two of the last three holes. It was really nice to finish like that."

By now, the spiel on McIlroy is well-known: It has been over 10 years since he won a major. He has had more close calls than any player and has fallen short at the Old Course in St. Andrews and other venues both new and familiar such as Valhalla Golf Club, the site of his last major win in 2014. McIlroy has tried new approaches and different methods to get himself out of his major funk.

But even though the major victories have not materialized, McIlroy remains steadfast in trying to reach the mountaintop again.

"I've had some success by the sort of mindset that I've brought in, especially last year at LACC," McIlroy said. "The golf course is a little different to what it was last year, but still the same strategy, same mindset. Just trying to hit it into the middles of greens and giving yourself chances every single time, taking your medicine if you do hit it into trouble."

In the past six years, McIlroy's best opportunities at ending his drought have come at the U.S. Open. He has finished inside the top 10 at each of the past five. Last year was his closest call, a second-place finish that left him only one stroke behind eventual winner Wyndham Clark. Earlier this week, McIlroy said that since 2019, he has shifted to a more disciplined approach at the U.S. Open.

On Thursday, he also credited that shift to an appreciation for the courses the USGA is using to host its tournaments.

"I've started to appreciate golf course architecture more and more as the years have went on," McIlroy said. "Just becoming more of a student of the game again, and I think because of that I've started to embrace golf courses like this and setups like this."

Beyond the newfound interest in a U.S. Open setup, McIlroy now finds himself in a unique but favorable position. Every time he has opened a major with a bogey-free round, he has gone on to win the tournament. Now, for the first time since the 2022 PGA Championship, where he led outright after the first round, McIlroy will have three days and 54 holes to see if he can find a way to remain atop the leaderboard again.

"The major championships that I've won or the ones that I've played well at, I've always seemed to get off to a good start," McIlroy said. "It's nice to get off to another one."

Cantlay's hot start to this tournament is less familiar. This is the first time the 32-year-old will hold a share of the lead at a major after the first round. On Thursday, Cantlay's putter was scorching hot, helping him get around the golf course in only 23 putts despite only hitting nine fairways and 10 greens.

Beyond Cantlay, those chasing the leaders include Sweden's Ludvig Åberg (4-under), who finished second in his Masters debut in April and is making his U.S. Open debut here. The 24-year-old Aberg hit every fairway Thursday and only missed two greens on his way to solo third place.

"Super happy with the way we hit it. Super happy with the execution today," Aberg said. "I felt it was really nice and very encouraging. All we can try to do is keep it up and make sure that we're ready to go tomorrow."

Frenchman Matthieu Pavon and 2020 U.S. Open winner Bryson DeChambeau, who has top-10 finishes in the two majors this year, including a runner-up at the PGA Championship last month, are tied for fourth place at 3-under, while Tony Finau and Tyrrell Hatton are tied with rookie Akshay Bhatia at 2-under. All three are looking for their first ever major victory.

Scottie Scheffler, the world's top-ranked player, has some work to do in pursuit of his third major. He bogeyed the par-4 third and spent the rest of the day over par, finishing at 1-over 71.

In total, only 15 players shot under-par rounds Thursday, highlighting the difficulty that Pinehurst No. 2 presents. Coincidentally, only 15 players finished under par after the first round of the 2014 U.S. Open at Pinehurst, too.