Henrik Stenson fired four birdies and an eagle in a six-under par 65 on Sunday to seize the third-round lead in the Deutsche Bank Championship.

The Swede's 13-under total of 200 was one stroke in front of American Rickie Fowler, with American Sean O'Hair and Aussie Matt Jones a further stroke back on 202 after a day when world number one Rory McIlroy and PGA Champion Jason Day were unable to make a move up the leaderboard.

"It was a good day out there," Stenson said. "I was striking it nicely today."

Day, the world number three who came into the tournament with a chance to supplant McIlroy atop the rankings, had a double-bogey, three bogeys and three birdies in a two-over 73 that left him tied for 25th on four-under 209.

"There's no excuse for poor playing," said Day, who saw a run of 22 straight rounds of par or better end. "I just wish I had a little bit more energy."

McIlroy, playing his second tournament since he was sidelined by an ankle injury in July, remained at 2-over after an even-par 71 at TPC Boston that included three birdies and three-bogeys.

McIlroy, winner of the 2012 Deutsche Bank title, birdied the par-five 18th to avoid a second straight over-par round.

But his inability to mount a challenge means Masters and US Open champion Jordan Spieth could again grab the number-one world ranking, even though the 22-year-old American missed the cut on Saturday and won't be around for the Labor Day holiday finish on Monday.

If Day doesn't win, and McIlroy finishes outside the top 10, Spieth could still regain the summit he reached with a runner-up finish at the PGA Championship and held for two weeks.

"It's a mathematical system with algorithms and all sorts of different things," McIlroy said of the two-year rolling points formula for determining number one. "It's not something I really worry about."

Stenson, runner-up to Day last week at the Barclays, is gunning for a second Deutsche Bank title. He won the event in 2013 on the way to winning the US PGA Tour's FedEx Cup playoff title and its $10 million bonus.

"It's always good to be back at a course where you've performed well and played well," Stenson said. "I'll just try to keep it going."

He had three birdies on the front nine plus an eagle at the par-four fourth hole.

"Set it off straight on line with the pin, which I was trying to do," Stenson said of his three-wood off the tee at the fourth, which left him a tough 20-foot putt. "It actually worked out perfectly."

- Nice birdie -

He parred the first eight holes of the back nine before rolling in a tough birdie putt at 18 that gave him the outright lead.

"I left myself a few good chances on the back nine, I just couldn't convert," said Stenson, who was pleased to keep a bogey off his card with a two-putt par at the par-three 16th. "Then the nice birdie on the last."

Fowler carded a 67, saving birdie at the last to stay within one stroke of Stenson despite finding only four of 14 fairways.

O'Hair carded a 67 and Jones a 68 for 202. They were one stroke in front of Scotland's Russell Knox, who posted a 68 for 203.

Charley Hoffman, who started the day with a three-shot lead after a second-round 63, fell six adrift after a five-over 76.
Source: AFP