Tulsa (Oklahoma),   India's Anirban Lahiri, who welcomed the arrival of his second child and had a nine-hole practice round with Tiger Woods on Wednesday, settled for a 73 to leave himself with some work to make the halfway cut at the PGA Championship here, his first major start in nearly three years.

The 34-year-old Lahiri opened his day with a bogey and birdie on the 10th and 11th hole and dropped a bogey on the fourth from the greenside bunker before taking a costly double bogey on the par-5, fifth hole after finding trouble in the greenside bunker.

The Indian is currently tied 78th along with 20 others heading into Day 2 of the second major of the year on Friday.

In-form Korean star KH Lee carded his lowest round in a major when he fired a 1-under 69 in the first round of the PGA Championship on Thursday to lie four strokes back of leader Rory McIlroy.

McIlroy's 65 is his best opening-round score to par in a major championship since he opened the last of his four major championship victories with a 5-under 66 at the 2014 PGA Championship at Valhalla. The Northern Irishman, won The CJ Cup last October for his 20th PGA TOUR victory, made four successive birdies on his outward nine before posting three more birdies against two bogeys to lead by one from Will Zalatoris and Tom Hoge.

Tiger Woods, winner of the 2007 PGA Championship at Southern Hills, cards a 4-over 74, while world No. 1 and FedExCup leader Scottie Scheffler opened with a 1-over 71.

The 30-year-old Lee, who successfully defended his AT&T Byron Nelson title on the PGA Tour last week, registered three birdies against two bogeys at Southern Hills in Tulsa to mark his first ever round in the 60s in his sixth career major start.

"Last week was a very happy time for me and my family, and hopefully I try to just keep the momentum well. Played well... I'm very happy now," said Lee, who sits as the highest placed Asian golfer in the year's second major at tied 16th place.

Compatriots YE Yang, who delivered Asia's first major victory at the 2009 PGA Championship, and Si Woo Kim, a three-time PGA Tour winner, opened with 71s for tied 38th position while Japanese star Hideki Matsuyama carded a 72.

Lee has not broken par in his five previous starts in the majors where he has yet to make a cut. He shot 78 and 77 at the PGA Championship last year after his winning breakthrough at the Byron Nelson and missed the cut at the Masters Tournament last month following rounds of 74-75.

However, he is now riding on new-found form and confidence after going back to work with his old swing coach Chris Mayson, and his former mental trainer. He won last week with a winning total of 26-under.

"I try a new challenge," said Lee of his major quest. "Just try to keep my momentum. I want to always play well every week. Hopefully, good for the whole week up until Sunday."

He three-putted his first hole on the 10th for bogey before turning in even par by rolling in a 20-footer for birdie on the 18th. He converted putts of eight and six feet on the first and fifth holes for further gains, sandwiching a bogey on Hole No. 2 when he found the greenside bunker.

First-Round Leaderboard

Rory McIlroy 65 (-5);

Will Zalatoris 66 (-4), Tom Hoge 66 (-4);

Matt Kuchar 67 (-3), Abraham Ancer 67 (-3), Justin Thomas 67 (-3).