LEMONT, Ill. — Tiger Woods started with a bogey. His best shot led to a par.It turned out to be his best round of the year.Getting better with every shot, Woods broke the course record at Cog Hill and blew away the field Saturday in the BMW Championship with a 9-under 62 that gave him a seven-shot lead."After I got past the first hole I was doing all right," Woods said. "It was one of those days that kind of built upon itself."Brandt Snedeker finished with four straight birdies for a 66 and will play with Woods for the first time Sunday. He could probably think of better circumstances."I've got to do something spectacular," Snedeker said, "and he's got to maybe have a heart attack out there for me to have a chance."Marc Leishman had a two-shot lead when he made the turn. Could he have imagined shooting 1 over on the back nine and finding himself seven shots behind?"You wouldn't think so," he said. "But like I say, it's Tiger."The 62 tied the tournament record — an event that dates to 1899 — set last year by Jim Furyk at Bellerive outside St. Louis.A course renovated by Rees Jones with hopes of landing a U.S. Open was no match for Woods, who was nearly nine shots better than the field, which averaged 70.71.Woods was at 16-under 197 and had his largest lead on the PGA Tour since he was eight shots in front in the Buick Invitational at Torrey Pines early last year. He wound up winning by eight shots.This was Woods at his finest, even though he wasn't flawless.He dropped his 3-wood in disgust after his opening tee shot sailed to the left into a bunker, leading to a sloppy bogey. He followed that by missing a 10-foot birdie putt on the next hole. Woods started the third round tied for the lead, and already was three shots behind when he stood on the tee at the par-3 sixth and faced a dangerous pin — all the way to the left, protected by deep bunkers front and back."Even if you bail out to the right, it's a tough putt," Woods said. "The only thing you can't do there is go in the back bunker. That's one of the reasons why I didn't hit a 6-iron and try to hold it in there. But I had to hit the 7-iron really good to get it there, and I pulled it off."From there, he never missed another green.He considers his best shot a 6-iron out of the rough on the left side of the seventh fairway, which he needed to start left of the green to avoid a tree in front of him and yet keep it out of the bunker. It came out perfectly, and Woods gave a light fist pump, rare for an iron shot that stopped 15 feet away on the fringe.The signature shot was a 3-wood from just over 300 yards to 10 feet at the par-5 ninth for an eagle, so pure that the gallery crammed into the bleacher rose to its feet when the ball finally stopped rolling.Woods knocked it to take the outright lead, and it only got bigger.It will be his first time with the 54-hole lead since the PGA Championship last month at Hazeltine, where Y.E. Yang made up a two-shot deficit and became the first player to beat Woods from behind in a major.Yang is 25 shots behind at Cog Hill.Snedeker was worried about keeping his card this summer until his health improved and his game turned around. Now he has a chance to move into the top 30 in the FedEx Cup standings, which would qualify him for all the majors next year.Winning this week? That's a taller task."Looks like Tiger is making it difficult on us," Snedeker said after closing with four straight birdies. "I'm playing fantastic. And the best thing is I fought extremely well out there."Matt Kuchar improved his Tour Championship hopes with a 66 and was tied for fourth at 205 with Padraig Harrington (69).It was Harrington who got Woods' attention early in the third round. The Irishman birdied three straight holes, chipping in on the fourth hole from deep rough, while Leishman birdied four straight in the middle of the front nine to reach 10 under.Woods stood on the sixth tee three shots behind. Four holes later, he had the lead to himself. And midway through the back nine, when he was firing at flags and holing putts, the tournament seemed to be over."It was just a round that, as I said, kind of built upon itself, and I just kind of gradually kept hitting good shots, then making a couple of putts here and there," he said. "And lo and behold, I end up at 9-under par."Woods will be going for his sixth victory of the year and his fifth at Cog Hill on Sunday, which would put him atop the FedEx Cup standings going to the Tour Championship in two weeks.For everyone else, it's a matter of getting there.Seven players among the top 10 are currently outside the top 30 required to get into East Lake. Snedeker would not have figured to be one of those players three months ago, when he was returning from a rib injury."I didn't think I was going to have a job in July," Snedeker said. "My whole goal was to secure my card. Now I'm back to my original goal of trying to make the Tour Championship. Any time you get to the Tour Championship, it's been a good year."