TULSA, United States (AFP) - Ernie Els refuses to say no one can defeat Tiger Woods in Sunday's final round of the PGA Championship, but even the three-time major champion from South Africa admits it is all-but over.

"If I was a fan on the couch I would be putting my house on it," Els said Saturday after firing a one-under par 69 at Southern Hills Country Club to stand on one-under 209 after 54 holes at the year's final major tournament.

Woods is 7-for-7 in winning majors when ahead after 36 holes and 12-for-12 when leading after 54 holes, as he has here. In the six prior majors at Southern Hills, every winner was ahead or sharing the lead after 36 holes.

"The statistics will tell you it's over but as a competitor I can't say that. There are 18 holes left to be played," Els said.

"He has got to make a lot of mistakes and I've got to play unbelievable. We all have to have the rounds of our lives and he has got to make a couple of mistakes. He is playing well right now and he has a lot of confidence."

Els has battled back to be among xxxx players under par entering the final round, but he knows Woods is deadly playing from the lead, especially on a course like Southern Hills.

"When you start pushing trying to make birdies and eagles, that's when the mistakes come. When you're leading you're fine," Els said.

"You always bring in a double bogey if you're aggressive off the tees. If I was leading I probably wouldn't be doing it, no."

Els, a former British Open and two-time US Open winner, said Woods has developed the patience to win at courses like Southern Hills.

"He has definitely figured out these short, twistier courses. I shouldn't say that. He has won 12 majors," Els said.

"You have got the best golfer in the world leading here. OK, he's leading by a bunch because we're shooting ourselves in the feet. If you play proper golf, you can score what he scores."

"I am what I am. Tiger is what he is. He isn't making the mistakes. If I can eliminate these mistakes I can start challenging for tournaments again."

Els could have been within reach if not for a double bogey at the fourth. He spent most of the round recovering from that and admits little mistakes nag at his game even as he approaches the form he needs to win majors.

"It has been a slow process for me. It's a bit of a battle with the game at the moment. I'm trying to keep my head down and stay into it," Els said.

"I've made 14 birdies this week and I'm one-under par. I've done a lot of good things this week. The frustrating thing that drives me nuts is I'm making soft mistakes out there. That drives me crazy.

"My game as a whole is pretty good. For some reason the game is testing me at the moment."

Els moved himself into the top five but knows that might not be enough without a round for the ages on Sunday.

"I was actually looking for a nice low round to try and get back into it," Els said. "I've got to be satisfied with where I finished. I was well out of it and I got it back into (below-par) red numbers."

"My goal for the weekend was to get to 10-under. I've just got to shoot 61 tomorrow."