Rory Sabbatini maintains four shot lead

Following the shock withdrawal of Tiger Woods because of flu, Sabbatini collected five birdies and a bogey to stay on course for the third PGA Tour title of his career.

His American playing partner Craig Barlow eagled the par-five 17th on his way to a 67 and a share of second place at 10 under with twice winner Fred Couples, who shot a 65.

Sabbatini, who has finished second twice in six PGA Tour starts this year, admitted he had not felt entirely comfortable with his irons.

"I'm probably going to switch my irons back out tomorrow, back to my old set, because my irons aren't feeling as confident as they should be," he told reporters.

"If I get out on the range tomorrow morning and they feel okay, they'll be in the bag."

The big-hitting South African, who won the PGA Tour's Air Canada Championship in 2000 and the FBR Capital Open in 2003, does not plan to change his strategy.

"I'm comfortable with the lead," he said. "I know I have to go out there tomorrow and do what I've been doing. If I limit my mistakes and give myself opportunities, hopefully something good will come out of it."

The 46-year-old Couples, champion at Riviera in 1990 and 1992, was roared on by large crowds as he picked up six shots over the last 13 holes.

"My days aren't exactly numbered but they are close to it in these tournaments," the 1992 U.S. Masters champion said. "I know this course very well. If I play well, I know the birdies will come."

South African duo Tim Clark and Trevor Immelman carded matching 67s to share fourth place at nine under.

A further stroke back in sixth was another American, John Rollins, whose best-of-the-day 64 included an eagle-two at the 10th.

Sabbatini, playing his sixth PGA Tour event in seven weeks, produced sparkling form from tee to green over the first six holes but missed three birdie opportunities from around six feet.

He finally picked up his first shot at the 408-yard seventh as bright sunshine replaced the early morning drizzle, hitting a superb approach to within three feet of the pin.

Out in one-under 34, he reeled off three birdies in a row. He cleared the left greenside bunker with his drive at the par-four 10th and chipped up to two feet, reached the green in two at the par-five 11th and holed a 15-footer at the 12th.

Although the Texas-based professional dropped his only shot at the 13th, where he drove left under trees before missing a six-foot par putt, he struck his nine-iron approach at the last to just four feet to sign off in style.

The biggest news of the day, however, was the withdrawal of the ailing Woods before he was scheduled to tee off.

Having narrowly made the halfway cut after bogeying his last two holes on Friday, the world number one was forced to end his bid for a third consecutive victory.

"Everyone saw how Tiger felt this week, struggling with the flu and he just can't shake it," Woods's manager Mark Steinberg said in a statement. "He feels awful. This is an event he loves to play in and strives to win."

It is the first time Woods has pulled out of an event for health reasons since turning professional in 1996.