Rory McIlroy used four straight birdies early in his round Thursday to shoot a 5-under-par 65 and take the first-round lead at the PGA Championship at Southern Hills Country Club in Tulsa, Okla.

The four-time major winner from Northern Ireland also birdied his final hole to move ahead of Will Zalatoris and Tom Hoge, who shot 66 during the early wave of golfers. Matt Kuchar, Justin Thomas and Mexico's Abraham Ancer are tied for fourth at 67.

A large group at 68 includes Xander Schauffele, Kevin Na, Australia's Cameron Smith, England's Matt Fitzpatrick and Chile's Joaquin Niemann.

McIlroy is a two-time PGA champion (2012, 2014), but since his title in 2014, he has yet to break through and win another major. He started slowly at the Masters last month but finished with a stellar 64 to wind up in second place.

"I've been carrying some good form," McIlroy said. "Obviously (I) took a lot from that last round at Augusta, played well up in D.C. at the Wells Fargo there and played good in the practice rounds earlier this week.

"I think when your game is feeling like that, it's just a matter of going out there and really sticking to your game plan, executing as well as you possibly can and just sort of staying in your own little world."

Playing in a group with Tiger Woods and Jordan Spieth, McIlroy started on the back nine and dialed up birdies at the 12th through 15th holes. At the par-4 12th, he stuck his second shot inside 2 feet of the pin for a tap-in. Another highlight came at the par-3 14th, where he rolled in a right-to-left birdie putt from 26 feet.

McIlroy added birdies at Nos. 2 and 5 to reach 6 under before giving those shots back by bogeying the next two par-3 holes, the sixth and eighth. But at the par-4 ninth, he sank a downhill 19-footer for birdie to move back into sole possession of the lead.

Woods started with two birdies in his first five holes before coming apart. He favored his surgically repaired right leg throughout the afternoon and finished at 4-over 74 after making seven bogeys and one more birdie. Spieth shot a 72.

"My leg is not feeling as good as I would like it to be," Woods said. "We'll start the recovery process and get after it tomorrow."

Zalatoris counteracted two bogeys with six birdies, including a strong finish with a 24-foot birdie putt at the seventh hole and a 30-foot birdie at the ninth.

"I think I either made four or five 25-footers," said Zalatoris, the 2021 PGA Tour Rookie of the Year. "It was kind of a bizarre day. ... Anytime you can put up a 66 in a major, you're obviously happy."

Hoge collected five birdies and just one bogey. He opened with a 15-foot birdie putt at the par-4 first and had three more birdies inside of 6 feet thanks to his approach game. The 32-year-old earned his first career PGA Tour win earlier this year at the ATT Pebble Beach Pro-Am.

"I felt like the golf course was a little bit softer than I expected it to be," Hoge said. "The greens were very receptive out there. So certainly felt like you could go out and do it and shoot a few under par if you played well, and I was fortunate to do so."

The winds picked up later in the day, leaving tougher scoring conditions for the afternoon wave of golfers. Thomas played in that wave and finished with three birdies and no bogeys over the back nine, including a 20-foot putt to become one of the few to birdie No. 18.

The top three players in the world ranking -- Scottie Scheffler, Jon Rahm of Spain and Collin Morikawa -- played in a marquee afternoon group and all struggled, combining for nine bogeys on the back nine.

Scheffler, the Masters champion, made four bogeys in his last seven holes with water balls on Nos. 13 and 18 -- though he recovered on the last hole to save par for a 71.

"I think you just try and use (frustration) for good," said Scheffler, who also eagled the par-5 fifth. "I was definitely very frustrated out there but just kind of hung in there. I made a great par at the last and that'll make dinner taste a little bit better."

Morikawa posted a 72, and Rahm struggled to a 73.