Rory McIlroy hit wedge into five feet for birdie on the 18th hole for a 2-under 70 to regain the outright lead in the Dubai Desert Classic on Friday.
The chief challenge for McIlroy came from an American, but it wasn't Tiger Woods.
Brooks Koepka, who earned his European Tour card last year by winning three times on the Challenge Tour, made seven birdies against no bogeys for a 65 that left him one shot behind McIlroy going into the weekend.
Woods, meanwhile, hit only four fairways and had to rely on some key putts to salvage a 73. He was in a tie for 44th, eight shots out of the lead.
McIlroy was at 11-under 133.
He appeared to be in control at Emirates Golf Club, leading by three shots after his birdie at No. 10. But he drove wildly into the waste area on the par-5 13th and the par-4 16th holes, both leading to bogeys, before recovering on the 18th.
"It was nice to birdie the last and at least give myself a one-shot lead going into tomorrow," McIlroy said. "I will just go back tonight and sort of regroup and realize I am still leading the tournament. I was more frustrated on the back nine, as the back nine is where you want to build your score after playing the harder front nine."
Danny Willett of England, who began his week by jumping out of a plane at 4,000 metres (13,000 feet), had a 65 and shared third place with Damien McGrane of Ireland (70) and Julien Quesne of France (70).
Henrik Stenson, who won the Race to Dubai and the FedEx Cup last year, had a 67 and was four shots behind.
'I was on so many parts of the golf course today that I got to meet so many people, signed so many autographs out there and gave a lot of balls away.' - A joking Tiger Woods
Woods, trying to join Ernie Els as the only three-time winners of the Dubai Desert Classic, opened with a birdie on his third hole and the highlights were few after that. His only other birdie was on the par-3 11th, with a shot into two feet.
Instead of going to the practice range after his round, he conducted a clinic with Mark O'Meara.
"I was on so many parts of the golf course today that I got to meet so many people, signed so many autographs out there and gave a lot of balls away," Woods joked with the crowd. "Seriously, I was just hitting it sideways."
He even joked about the 79 he shot last week at Torrey Pines to miss the 54-hole cut on a course where he had won eight times previously, including a U.S. Open.
"I have to tell everyone here I never made a 10-footer for not shooting 80," Woods said.
As for his round on Friday, he said he putted well, but had too many putts from 40 and 50 feet, which is "not exactly the best thing."
"I just didn't hit it close enough and didn't hit it well," Woods said. "I struggled with it and had a bad warm-up, as well. Just one of those days."
Koepka is in his first full season on the European Tour. He came close to winning the Frys.com Open last autumn in America before struggling on the back nine. He is roommates in Florida with another American on the European Tour, Peter Uihlein, who bogeyed his last hole to miss the cut.
"Winning is winning," said Koepka, who has four Challenge Tour wins. "I've been able to do it on the Challenge Tour, so hopefully I can get it done with week."
It should be more difficult with McIlroy, a two-time major champion, starting to regain his form. McIlroy ended a year without winning in December when he edged Adam Scott at the Australian Open. He finished one shot behind in Abu Dhabi two weeks ago.
"I'm leading the golf tournament. I've been in this position before and I've went on to win," McIlroy said. "I've led from the front quite well in tournaments that I have won. I feel like I am still playing well and I know the course just as well as anyone else. I'm now expecting to go out there and shoot two good scores over the weekend and hopefully lift the trophy."
Willett, along with his wife and caddie, began the week with an assisted sky dive on Monday in a charity event. He feels it might have helped with his golf.
"If you stand on the first tee, trying to hit a drive into the fairway seemed a little bit less nerve-racking than jumping out of a plane at 13,000 feet," Willett said. "You never know, might have prepared us quite well."