Brooks Koepka produced a stunning start to his PGA Championship title defence to open up a one-stroke advantage after his record-breaking opening round.

Koepka broke the course record at Bethpage Black after firing seven birdies on his way to a bogey-free 63 on Thursday morning, equalling the lowest round in the tournament’s history and becoming the first player ever to shoot multiple 63s in the same major.

The defending champion’s closest challenge comes from New Zealand’s Danny Lee, who birdied his last two holes to close a six-under 64 and register the lowest round of the afternoon starters, with Tommy Fleetwood a further three strokes back in third.

Starting on the back nine alongside Tiger Woods and Francesco Molinari, Koepka holed a 40-footer at the par-four tenth and followed a missed chance from eight feet at the next by draining a 20-footer at the 14th and picking up a shot at the 18th.

Turning in 32, Koepka’s ball-striking masterclass continued at the first to set up a close-range birdie, before the 29-year-old picked up shots at the third and fifth to pull clear at the top of the leaderboard.

After scrambling to make a 10-footer and save par at the sixth and making pars over his next two holes, Koepka rolled in a 30-footer at the ninth – his final hole – to finish four shots better than any of the morning starters.

Lee made his move up the leaderboard with four birdies in a five-hole stretch around the turn, with the New Zealander converting a 12-footer at the 14th to get within two of Koepka’s clubhouse target.

The world No 119 recovered from bogeying the 15th by firing his tee shot at the par-three 17th to five feet and making birdie, before converting from 15 feet at the last to finish on six under.

Only 16 players ended the day under par in New York, with Fleetwood in third spot on three under and world No 1 Dustin Johnson in the group six of the pace that also includes Phil Mickelson, Jason Day and Jordan Spieth – who can complete the career Grand Slam with victory this week.

Woods, making his first start since winning the Masters last month, double-bogeyed his opening hole and carded a double-bogey at the par-three 17th on his way to a front-nine 38.

The former world No 1 posted back-to-back birdies from the first and made a 30-foot eagle at the fourth to get into red figures, only to drop three shots in the next four holes and finish nine strokes off the lead.

McIlroy – grouped with Mickelson and Day – is also in the group on two over after a frustrating start to the week, with the Northern Irishman saving his only birdie of the day for the par-four last.

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(c) Sky News 2019: PGA Championship: Brooks Koepka off to bogey-free start at Bethpage