Westwood mixed two bogeys with three birdies to reach a 13-under 203 total, while fellow Englishman and playing partner Ross Fisher had to settle for a 73 on a hot day at Sun City, made tougher by a swirling wind around the Gary Player Country Club.
Fisher was tied for second with South Africa’s Tim Clark, who shot 68, one of only two sub-70 rounds on Saturday in the 12-player invitational tournament.
Fisher trailed Westwood by three shots overnight but had two bogeys and a double bogey in four holes from No. 14.
“Three ahead (yesterday), now five ahead, I’ll take that,” Westwood said. “It was tricky out there today. To come out five shots ahead is a big bonus.”
Spain’s Miguel Angel Jimenez was 7 under and alone in fourth. Anders Hansen of Denmark, whose 68 matched Clark for the day’s best round, is tied for fifth at 6 under with Ernie Els and Padraig Harrington – who had a second successive 72 to fall further off the pace after having taken the lead with a first-round 66.
The No. 1-ranked Westwood didn’t come close to his second-round 64, but he shrugged off his two slips late on and is in sight of just a second tournament win of 2010.
“I’ve made three bogeys in 54 holes so that’s pretty good going,” he said. It’s a nice position to be in but it’s by no means over. It can change pretty quickly.”
Fisher had applied some pressure with birdies on holes 3, 9 and 12 and hadn’t dropped a shot until he found heavy rough with his driver on No. 14 and again on No. 15. He bogeyed both.
He parred the short par-3 No. 16 but found the water on 17 and came away with a double bogey – for four dropped shots in four holes.
“Disappointed? You could say that,” Fisher said. “It was going swimmingly through 13 (holes). It was just a disappointing day. Five behind now, it’s going to be difficult. I’m going to have to shoot a real low number tomorrow.”
Clark climbed into contention with his 68 after a stunning approach to the par-4 No. 18 that pitched on the front of the green and kicked to within three feet of the hole.
It led to a fourth birdie for the South African, who was bogey-free and will be paired with Westwood Sunday.
“I’m starting quite a long way back tomorrow, that probably makes it a little easier. You can come out and be aggressive and not worry about protecting anything,” Clark said. “I think tomorrow will be a fun day.”
Edoardo Molinari’s challenge also faded with a 73 to fall from a tie for third to eighth on 5 under.
Retief Goosen (70), defending champion Robert Allenby (73), Justin Rose (72) and Louis Oosthuizen (72) round out the last four places on the leaderboard.