-- Vijay Singh has experimented with close to 400 putters and countless grips over the course of his career, including the belly-style model he has used most of the last two years. Two weeks ago, he went back to a standard putter and a conventional grip and won the Buick Open, and now he's threatening to prevail for the fifth time this season after a 3-under-par 69 in the third round of the 86th PGA Championship.

Singh, a two-time major champion who has gone 18 straight majors since the 2000 Masters without winning a third, began the day tied with playing partner Justin Leonard, the 1997 British Open champion who hasn't won anything since February 2000. Only a sloppy bogey out of a deep greenside bunker at the 500-yard 18th hole cost Leonard a share of the 54-hole lead.

Singh came in at 12-under 204 after making an eight-foot par putt at the 18th, with Leonard a shot behind after his 70 -- 205, and the two men will once again play in the final group Sunday.

"It doesn't really bother me when I'm leading a tournament and lose the lead in the first three or four holes," Singh said. "I keep telling myself it's an 18-hole event, and that's what I'll do [Sunday]. I'll try not to make mistakes, pick up a few birdies on the first few holes and go on from there. I feel comfortable in the lead. The person behind has to play one shot better."

At a Whistling Straits course that continues to be mostly docile, six players are within four shots of Singh's lead, including Ernie Els, the No. 2 player in the world (72 -- 208) and No. 3 Phil Mickelson, who shot the day's best round of 5-under 67 for a 208. Irishman Darren Clarke (72 -- 208) survived a shank that cost him a bogey at the 17th and will attempt to become the first European to win the PGA Championship since Scotsman Tommy Armour in 1930.

Fast-closing American Chris Riley (69), with birdies on two of his last three holes, and Stephen Ames (69) of Trinidad and Tobago, who bogeyed his final hole, also are at 208, with Chris DiMarco, fighting for an automatic berth on the U.S. Ryder Cup team, in eighth place after his 71 -- 209.

Leonard shrugged off a bogey on his first hole Saturday to set himself up nicely to win the second major championship of his recently stalled career. Leonard was in an even better position two years ago in the PGA at Hazeltine in Minnesota, holding a three-shot advantage after 54 holes. But he got off to a miserable start in the final round and ended up shooting 77, falling back to a tie for fourth.

"I've gained a lot of perspective in the last couple of years since Hazeltine," Leonard said, adding that "what I do [Sunday] is not going to define the player that I am or the person that I am to myself, and it really shouldn't for anyone else. If I can keep that in my thoughts, I'll have a better chance of not worrying about trying to win a golf tournament. . . . I'm going head-to-head with one of the best players in the world, if not the best, and it should be challenging."

Singh is the PGA Tour's leading money winner this season, and a victory on Sunday likely would make him the favorite to be named the PGA Tour's player of the year. Singh has won the past seven tournaments in which he either held or shared the 54-hole lead.

For the fourth time this season, Els, despite a bogey at the final hole, also got himself into prime position to win the fourth major of his career. A victory here would surely take some of the sting away from runner-up finishes in the Masters and British Open, and a ninth place ending at the U.S. Open. Els hasn't led after three rounds of any major this year but hadn't been less than three behind entering the final 18 of any of them. For Tiger Woods, the day began with great promise with birdies on three of his first five holes, but another camera click as he was coming down on his swing forced him to back off his shot, then lose his focus with a wild tee shot at the 221-yard hole that resulted in a bogey. He had another bogey at the 143-yard 12th and parred in for his second straight 69, but will begin play Sunday nine shots off the lead.

For the second straight season, Woods will go winless in the majors, a streak that will increase to 10 after Sunday barring a miracle, and he admitted that some frustration is clearly setting in.

"It's getting frustrating that I was not able to put myself up there," he said. "By putting as poorly as I did Thursday, I just put myself too far back. Expecting to play and make a bunch of pars and expect to get back in the tournament, I needed to go out there and be aggressive and make a bunch of birdies. The past few majors, that's what ends up happening."

Mickelson had no such problems. Starting his day six shots off the lead, the Masters champion who was runner-up at the U.S. Open and third at the British, launched himself into contention with a 5-under 31 on his front nine, the lowest score of the day on that side. A three-putt from 70 feet at the 618-yard 11th led to his only bogey of the afternoon, and a two-putt birdie at the 569-yard 16th pushed him to 8 under for the tournament.

Mickelson had already made a 50-footer to save a par at the fifth hole and added another brilliant save at the 500-yard par-4 18th to preserve his round of 67. After a drive down the middle, his second shot came up short of the green and landed in a bunker, well below the hole. Mickelson hit a high-soaring shot out of the sand, and it stopped about 10 feet behind the hole. But his par putt was straight and true, and he ran up the hill toward the scorer's hut with a beaming smile at the prospect of once again being in the hunt Sunday in a major championship.

"You want to be in the lead," Mickelson said. "The only time I've led after 54 holes, I was able to win . . . the Masters. It's much easier having a couple of shots in hand than it is trying to chase because you don't have any room for error. If you make a bogey or two, you have to press and make more birdies, but at least I have a chance."

Clearly, he's not the only one.

Justin Leonard, right, studying a putt with Vijay Singh: "I'm going head-to-head with one of the best players in the world, if not the best, and it should be challenging."Ernie Els, lining up a putt, is four shots back and in contention for the fourth major of his career. Tiger Woods, who shot his second straight 69, trails by 9.