– The Associated Press

LOS ANGELES – Bill Haas had no reason to think this round at Riviera was going to be anything special.

With an iron in his hand, he failed to make birdie on the par-5 opening hole, the easiest on the golf course. Solid iron shots led to a pair of birdies on the front nine, and with Riviera playing tough in warm, dry conditions Saturday, he was part of a large group challenging for the lead.

Three holes changed everything.

Haas made a tough 30-footer for birdie on No. 9. He pitched in from 60 feet for eagle on the scary par-4 10th. And he hit a good bunker shot with little margin for error on the par-5 11th that set up a birdie.

Just like that, he was on his way to a 7-under 64 and a three-shot lead going into the final round of the Northern Trust Open.

His 64 was the best round of a difficult day by three shots, and it was nearly eight shots better than the average score. It put Haas at 12-under 201, leaving him in good position to become only the eighth back-to-back winner in the 76-year history of this tournament.

All he cares about Sunday is winning.

“It’s very difficult in this game to just pull away from the rest of the field,” Haas said. “You’ve only seen a few guys ever really do that, and those are guys like Jack Nicklaus, Tiger Woods, Phil Mickelson. So I think I’ve just got to stay in the moment, don’t let my emotions get the best of me.”

A year ago, Haas was two shots behind going into the final round and wound up winning in a playoff over Mickelson and Keegan Bradley. This time, he has a comfortable margin over U.S. Open champion Webb Simpson and former Masters champion Charl Schwartzel, who each thought they did well for a 68.

John Merrick bogeyed the 18th hole for a 70 and joined Simpson and Schwartzel at 9-under 204.

EUROPEAN TOUR: South Africans Darren Fichardt and Jaco Van Zyl shared the lead going into the final round of the Africa Open, two shots clear of their nearest pursuers at East London, South Africa.

Fichardt had a 65 in the third round, setting up a great day by firing four birdies and an eagle on the first eight holes, but a bogey on the 17th dropped him back to 15-under 129 and into a tie with Van Zyl, who had a 68.

Second-round leader Adilson Da Silva had a triple bogey on No. 8 and finished with a 73 to fall two shots off the lead. France’s Gregory Bourdy was another stroke back after a 67.

CHAMPIONS TOUR: Bernhard Langer shot a 2-under 70 to take a three-shot lead after the second round of the Champions Tour’s ACE Group Classic at Naples, Fla.

Langer, who had a 10-under 62 in the first round, picked up where he left off with a birdie on his first hole. He made 11 straight pars after that, birdied No. 13, and had a par on the last five holes in windy conditions. He was at 12-under 132.

Taiwan’s Chien Soon Lu and Tom Pernice Jr., the runner-up last week in Boca Raton, Fla., were tied for second at 9-under 135.

WOMEN’S AUSTRALIAN OPEN: Jiyai Shin of South Korea and 15-year-old amateur Lydia Ko each shot three-under 70 to surge six shots clear of the field heading into the final day at Canberra, Australia.

Ko, a South Korean-born New Zealand-based player who already has three wins in pro events, jumped into an early lead with birdies on the 2nd, 4th and 6th holes. She allowed Shin to retake a share of the lead with bogeys on No. 12 and 14 before making another birdie on the final hole to finish 17-under 202.

Shin, a two-time British Open winner, made an eagle out of the green-side bunker on the par-5 6th, but gave up a chance of an outright lead when she had a bogey on the penultimate hole.