Louis Oosthuizen of South Africa hits from a bunker on the fifth hole at Quail Hollow on Thursday. Photo: Chuck Burton, AP

CHARLOTTE, North Carolina – Denmark’s Thorbjorn Olesen closed with a 27-foot birdie putt on Thursday to seize a one-stroke lead at the PGA Championship, while Jordan Spieth stumbled in launching his career Grand Slam bid.

The 78th-ranked Dane birdied three of the last five holes to fire a four-under-par 67 at Quail Hollow, one stroke ahead of US Open winner Brooks Koepka and his fellow Americans Gary Woodland and Grayson Murray.

“I just felt like I was playing nicely,” Olesen said. “The first 15 holes I played really well. I putted very nice.”

Olesen, 27, seeks his first major title. His most recent of four career European Tour victories came at last year’s Turkish Airlines Open. But he is fighting to keep the excitement and pressure well managed.

World number two Spieth, who won his third major title at last month’s Open Championship, struggled with his putter in firing a 72. At 24, he would become the youngest on the career Grand Slam list by winning the Wanamaker Trophy this week.

“Tee to green it was pretty solid,” Spieth said. “On the green was the problem. My speed and lines were a little off.”

Spieth, who also won the 2015 Masters and US Open, can become only the sixth man to sweep the four current major titles in a career after Jack Nicklaus, Tiger Woods, Ben Hogan, Gary Player and Gene Sarazen.

Koepka, who captured his first major title in June at Erin Hills, had five birdies and two bogeys, the last at 16 to fall back. He has again peaked at the right time, he said.

“These are the events where you want to play your best,” Koepka said of majors. “Sometimes it’s a lot simpler than people think. It just comes down to preparation.”

Jordan Spieth, left, and Brooks Koepka walk to the 13th green. Photo: Chris O'Meara, AP

World number one Dustin Johnson, in a pack on 70 that included South African Louis Oosthuizen, Australia’s Jason Day and Japan’s Hideki Matsuyama, said putting was as tough as he has seen all season.

“It was tough to get the ball close to the hole,” he said. “I’m very pleased with that the way the course played.”

Spieth, who began on the back nine, birdied the par-5 15th, but found a greenside bunker at 16 and missed a 14-foot par putt, then missed 10-foot par putts at the first fifth and par-3 sixth holes.

He answered with birdies from three feet at the par-5 seventh and inches from the cup at the par-4 eighth.

“It was a day that should have been a couple under par and ended one-over,” Spieth said. “It’s a little disappointing, but I brought it back with a couple birdies to at least having a chance going forward.”

Among afternoon starters, fourth-ranked Rory McIlroy was level-par after four holes and South Korean An Byeong-Hun was three-under through five after opening on the back nine with three consecutive birdies.

Northern Ireland’s McIlroy, 28, could become only the third player to win five majors before turning 30, joining Nicklaus and Woods. He has two PGA titles and two wins at Quail Hollow in US PGA events.