The leader board wasn’t quite as long as the phone book but there was a throng still in contention as darkness closed in on the Saturday of the 2012 Shell Houston Open. Still and all, Louis Oosthuizen, all 5-foot-10 of him, loomed above the crowd after a 66 that pushed his score to 17 under.

The South African frequent flier – he is competing on both the U. S. and European tours and playing back home as much as possible – accomplished this feat despite burping badly out of the gate. He found two bunkers on No. 1 and bogeyed that hole and the next before righting the ship with three straight pars.

He birdied three of the last four holes on the front to get back on the friendly side of par, turning in one under, but it was on the back side that the magic came pouring out. He rolled in birdies on 12, 13, 14 and 15 and tacked on another on 17. At the last, he saved par from the bunker right of the green to preserve his two-shot lead over Mahan.

Carl Pettersson (67) and Brian Davis (69) trailed by three with James Driscoll another shot back. Defending champion Phil Mickelson, who had opened in 65, posted his second consecutive 70 and was tied with Keegan Bradley and Ryan Palmer six off the lead.

The spring breeze that golf’s elite have come to expect at Redstone Golf Club put in an appearance, helping to dry the track after the 1.25-inch rain on Thursday that pushed the end of the second round back into Saturday morning. Oosthuizen and some of his closest pursuers wrapped up the third round shortly before dark.

By then, the leader was not only high and dry but waxing lyrical. “It was such a beautiful back nine with the weather and the sun dropping, I just felt I was playing down into the sun and the golf course looked spectacular . . . I mean, if you play well and you’re playing on a great course like that I think it gives everyone a boost.”

Not everyone was quite that enraptured. Like Oosthuizen, Mickelson stumbled early. On No. 4, he stood over a 25-foot eagle putt and took par, missing a birdie try of less than three feet. On No. 6, he chili-dipped and made bogey.

Still, he pronounced himself pleased with his play. “I hit the ball well,” he said. “I was patient all day and had a lot of putts lip out. I know I need to shoot a really low round but I know I can do it. I’ve done it. With the conditions right now, you can shoot six, seven, eight, nine under par, and that’s what I’m going to be shooting for tomorrow.

”He had changed putters “for alignment purposes,” but just for the day. Those putts that scared the hole “are going to have to fall tomorrow and I think they might.

If not, Oosthuizen might throw a glance over his shoulder at his playing partner. Mahan does not have a major championship to put up against the leader’s 2010 British Open title but he won the WGC Accenture Match Play Championship this spring and is closing in on $2 million in earnings already this year.

He didn’t appear to be suffering from the jitters. Need a good round Sunday to go into the Masters on a roll? “It’s not important,” he said. “I know my game is good. Whether I win tomorrow or don’t play well, it’s not going to knock me off too much. We play too much golf for one round to mean more than any other round.”

The Dallas resident has finished in the top eight here three times in the last five years and his 65 on Saturday was his lowest score of the year. Oosthuizen can counter with the lowest 54-hole total since the event moved to the Tournament Course in 2006. The winner will pocket $1,080,000.