After Tiger Woods maintained his commanding seven-shot lead at the WGC-Bridgestone Invitational on Saturday, his closest rivals all but conceded that Sunday's final round will come down to a battle for second.

Woods put himself in prime position to seal a record eighth victory in the elite World Golf Championships (WGC) event at Firestone Country Club, shooting a two-under-par 68 on Saturday to post a 15-under total of 195.

"It's tough when a guy is at 15 under and he's got a seven-shot lead," said American Jason Dufner, who birdied the first four holes on the way to a 67 and third place at seven under. "This would be a heck of a tournament for the fans and everybody out here if he wasn't playing, but that's not the case right now.

“He’s the type of golfer that can do this to these golf courses, and as players you’ve got to try and respond with what you can to try and catch him. It’s a tough task.”

Dufner was happy enough with his own form at Firestone, having produced scores of 67, 69 and 67 on a challenging, tree-lined layout that measures 7,400 yards off the back tees.

“The first three days have been pretty good,” the 36-year-old, a double champion on the PGA Tour, told reporters. “I’m right there up close to the top of the leaderboard, not really close to what Tiger is doing, though.

“He has a pretty good track record here. There are quite a few events out here where he does really well. He obviously feels comfortable on those courses.”

Woods has dominated the WGC events since they were introduced in 1999, winning 17 of them in 41 starts, and Henrik Stenson was fully prepared to watch the world number one romp to yet another victory on Sunday.

“We might just be there to see the final victory lap,” said the Swede, who will play with Woods in the final pairing at Firestone after a 67 on Saturday secured him outright second place at eight under. “We’ll see tomorrow. But I can only do so much. I can play my game and see where that takes me. It’s kind of tough to pick up seven shots on Tiger around here.

“It would take something spectacular on my behalf or any of the other guys around me and obviously a very, very poor one for him.”

Stenson, a seven-times champion on the European Tour, was excited about the chance to match up his game with Woods in the final round.

“He’s obviously playing great, and it’ll be a good test, a good measurement,” the 37-year-old said. “If he’s too far ahead, he’s too far ahead. It might be a race for second, but we’ll see tomorrow.”

Asked for his thoughts on why Woods played so well at Firestone, which has been softened by rain this week, Stenson replied: “When it’s soft, like now, you can flight the ball in and it’s proper target golf. He’s got great yardage control.

“He obviously likes to move the ball a little bit and a lot of the tee shots set up nicely for that. But it’s kind of hard to imagine. I never won anywhere seven times before, and he’s going for the eighth one here. He’s obviously very confident around this golf course, and he likes it. He just feels right at home.”

Rory McIlroy (69) and Phil Mickelson (67) both ended the third round on even for the tournament and well out of contention. The Irishman would also have shot a 67 were it not for late bogeys at 17 and 18.

Graeme McDowell was three over after a third 71 and Shane Lowry remained on eight over with a level par 70.