US unless stated -12 Vijay Singh (Fij) -11 Justin Leonard -8 Ernie Els (SA), Darren Clarke (GB), Stephen Ames (Can), Phil Mickelson, Chris Riley -7 Chris DiMarco -6 Brian Davis (GB), Loren Roberts Clubhouse scores

Vijay Singh will take a one-shot lead into the last round of the USPGA, but a host of big names remain in contention for the year's final major.

Singh's playing partner Justin Leonard bogeyed the last to fall back to 11 under, one off the Fijian's pace.

Three shots further back are Ernie Els, Phil Mickelson, Darren Clarke, Stephen Ames and Chris Riley.

Mickelson tied for the round of the day with a 67, while Els and Clarke could only manage level-par 72s.

Singh, the world number three, is chasing his first major title since the 2000 Masters.

"I'm quite happy with the way I'm playing," said Singh. "I've worked hard for this."

The 41-year-old, who won this event in 1998, has already picked up four victories on the PGA Tour this year, two more than anybody else.

Singh started slowly on Saturday, but with the conditions ripe for low scores at Whistling Straits he picked up four birdies from the sixth to return a three-under 69.

Anything can happen on this course Ernie Els

Leonard, the 1997 Open champion, also made a poor start, bogeying the first. But by the time he had added his fourth birdie of the day at the 12th, the 32-year-old Texan was two shots clear.

Two bogeys down the stretch changed that, and now he, and the rest of the field, must chase a player who has held on to the last seven 54-hole leads he has held.

"It's going to be a fun day," said Leonard. "I get to go head-to-head with one of the best players in the world, if not the best player in the world.

"At the same time, I have to play a (designer) Pete Dye golf course that's pretty difficult."

World number two Els will be kicking himself after an untidy back nine. Having already picked up second-place finishes at this year's Masters and Open, the South African is desperate to land a fourth major title.

Wayward driving brought two bogeys in his last two holes, but he has not given up hope.

"Anything can happen on this course," Els said.

It was outrageous - as good a shank as you are likely to see Darren Clarke

One shot behind the five-strong group on eight under is American Chris DiMarco, currently 15th on the US Ryder Cup list and in need of a good finish to force his way into Hal Sutton's team for Detroit.

Completing the top 10 are England's Brian Davis and veteran American Loren Roberts, tied at six under.

Clarke, who was celebrating his 36th birthday on Saturday, will need to repeat the kind of form he showed in the first round if he is to become Ireland's first major-winner since Fred Daly in 1947.

Academy: Darren Clarke's putting challenge

And part of the reason for that was a shanked tee shot at the short 17th that sent the ball some 70 yards right of the green.

"It was outrageous - as good a shank as you are likely to see," said Clarke.

The end result of Clarke's miscue was a "good" bogey. Just how good a bogey it was became apparent a few minutes later when Briny Baird triple-bogeyed the same hole to crash out of contention.