World No.1 Tiger Woods shot a blistering career best-tying nine-under-par 61 in the second round of the World Golf Championships Bridgestone Invitational to take control and lead by seven at Firestone Country Club.
The 14-time major winner flirted with a rare 59 after opening the back nine with four straight birdies but parred the final five holes to settle for 61, equalling his own career and course record mark.
Woods is odds-on to claim a record eighth title at the event despite still having 36 holes to play.
He has already claimed four victories this season and also has 17 WGC wins in 41 starts in the lucrative tournaments but last won at Firestone in 2009.
With 78 career wins so far, he is also closing in on Sam Snead's all-time US PGA tour win record of 82.
Defending champion Keegan Bradley (68) and Englishman Chris Wood (68) share second at six-under, seven off the pace, while Bill Haas (68) and Henrik Stenson (70) are tied fourth at five-under.
Adam Scott is the best of the Australians after following up his opening-round 73 with a more-precise 68 to be one-over, a monumental 14 shots off the pace.
"I had a lot of control today from tee to green and obviously the way I putted," Woods said.
"I felt I was in total control of my game. Obviously things like that don't happen every day, and it's fun when it all comes together and I was able to take advantage of it."
Woods started his second round two shots in arrears but had wiped out the deficit and stolen the lead within two holes.
He birdied the first, eagled the second and birdied the third to get the party started.
Another birdie on the seventh secured a 30 on the opening nine before he rattled off four in a row to start the back nine, well and truly bringing 59 into play.
Missed chances at 15 and 17 left him short of being just the sixth player to break 60 in US Tour history.
Woods claimed nerves weren't a factor, especially since Firestone is a par-70.
"The funny thing is I didn't feel uncomfortable at all about being there," he said of the magic number.
"The good news is I have shot it before at home back in '97 and, to do that at the time at my course, you had to be 13 deep.
"I was only nine today at that point and I've been 10, 11-under par before out here, so to be nine is nothing that was uncomfortable or unusual.
"It certainly was an opportunity but, when you're playing a par-70, it's certainly a lot easier."
Scott was happy to have turned the corner with his swing after a poor opening round but has all but conceded victory to Woods.
"I'd like to have a really hot weekend and maybe finish second," he said.
"I played good today. I worked on a few things yesterday on the range and sorted it out and now I'm feeling good.
"I'll work some more this afternoon and hopefully get it more locked in for the weekend and next week.
"There are obviously low scores out there. You have to hit fairways and get a hot putter. Tiger's done it heaps - I've had some low ones here a few times. It's all right there in front of you. You just have to do it."
Jason Day (72) is tied 59th in the 73-man field at six-over while Brett Rumford (74) is 71st at 10-over.
Australian PGA Championship winner Daniel Popovic continued to struggle, shooting 77 to be 16-over in last place.
