Schwartzel sits at 21-under 195 entering Sunday's final round, 10 shots clear of Frenchman Gregory Bourdy, who is in second. The former Masters champion recorded his first bogeys of the week Saturday, but 10 birdies across Leopard Creek Country Club more than offset them.
'I'm just playing the game right at this stage. Thinking well and placing the ball in the right spots,' said Schwartzel, who began the third round tied with Bourdy atop the leaderboard. 'Probably the biggest thing of all – I'm converting the putts.'
A winner four times this year on the European Tour, Branden Grace moved into a three-way tie for third behind a 5-under 67 Saturday. The focus, though, remains on Schwartzel, who is closing in on his second win in as many starts after winning by 11 shots last week in Thailand.
'It's a nice comfort, and I'd rather be 10 ahead than nine ahead,' he added. 'Whatever lead you can build is great.'