FARMINGDALE, N.Y. – Brooks Koepka’s PGA Championship title defense is off and running in record-setting fashion.

Nine months after lifting the Wanamaker Trophy at Bellerive, Koepka barely broke a sweat in his opening round at Bethpage State Park, carding a bogey-free 63 that left him four shots clear of anyone else in the morning wave.

Koepka’s score set a new record on the Black Course, and he’s now the only man to shoot multiple rounds of 63 in the same major championship. He also became the first player to ever shoot a 63 in consecutive years in a major, having done so during the second round last year in St. Louis.

PGA Championship: Scores | Full coverage

“I had good reads all day. The speed control was very solid,” Koepka said. “I felt very comfortable with the putter after a couple of changes we made, and very pleased with the way I putted today.”

Koepka started his round on the treacherous 10^th hole; while many players struggled to save par, he instead opened his morning with a birdie. That set the tone for a relatively stress-free stroll, as Koepka was the only player to go bogey-free in the morning. He set the new course record despite not making birdie on either of the Black Course’s par 5s.

“He hit a couple loose tee shots today that ended up in good spots, but I think that was probably the highest score he could have shot today,” said playing partner Tiger Woods. “He left a few out there with a couple putts that he missed. But it could have easily been a couple better.”

Koepka’s score vaulted him to the top of the leaderboard, as only Tommy Fleetwood (67) shot better than 68 from the early wave. It puts Koepka in position to contend for a piece of history this weekend: After winning the U.S. Open each of the last two years, he could become the first player ever to hold back-to-back titles in two different majors at the same time.

Should he retain the trophy, it would be another remarkable tally for a player who was major-less less than two years ago. And while tournaments aren’t decided on Thursday, the defending champ certainly took a step in the right direction.

“I’ve never been this confident,” Koepka said. “I think I’m still learning, understanding my game, and I’ve figured it out. And I think over the next few years, I’m excited about what’s to come.”