Rivals face a tough Sunday challenge PGA Championship 2007

Tiger Woods goes into Sunday's final round of the U.S. PGA Championship with the fans and most of his rivals expecting him to clinch his 13th major title.

The world number one is three strokes clear of the chasing pack and is 12-for-12 in winning major championships when holding at least a share of the 54-hole lead.

"If I was not a golfer but a fan on the couch, I'd be putting my house on him," Ernie Els told reporters after climbing into fifth place after shooting a one-under-par 69 on Saturday.

"Tomorrow is the final day and there are 18 holes of golf left to be played. Statistics will tell you, yes, it's over. But, as a competitor I can't sit there and tell you it's over.

"I gotta play the round of my life," added the three-times major champion, who trails Woods by six shots going into the last day at Southern Hills Country Club.

"We've all played rounds of our lives and he's got to have a couple of mistakes. But he's unbelievably solid at the moment, as we all can see, and full of confidence."

The big South African birdied four of his last nine holes on Saturday for a one-under total of 209 but knows he faces a formidable challenge if he is to overhaul the game's leading player.

"I was trying to shoot 65 today," the 37-year-old said. "My goal over the weekend was to try to get to 10 under. So I've just got to shoot 61 tomorrow."

Australian Adam Scott, tied for sixth place at level par after carding a 70, also accepts history and form are firmly in Woods's favour.

"You never want to say that but certainly he's proved that he's very hard to catch up to in a major," he said.

"But you know, there have been 63s out here so someone can go out and play the round of their life, put a little pressure on him.

"I feel like I'm very close to playing very well," added the 27-year-old from Adelaide. "If I can get off to a start like I did today and keep it going, you never know. I don't fear going low, that's for sure."