Leishman, who lost in a play-off for The Open Championship this year, birdied the last two holes for a 14 under par total at the Gary Player Golf and Country Club in Sun City, one shot ahead of World Number Seven, Stenson, who led for most of the day until two bogeys in the last three holes undid his earlier progress.
“It was a good day, said Leishman. “I got the speed of the greens a lot better today. I’d been missing a lot of putts low all week from hitting them a bit soft, so I fixed that today and managed to hole some putts. It was a great way to finish. I saw Henrik was getting away a little bit so I had to try to do something to make it interesting for tomorrow.
“I’ve been in this position a few times in big events so it’s great to draw on that experience. I’ve come up short a couple of times but I’ve won tournaments before and I’m looking forward to having a chance tomorrow.”
Leishman stands to win the equivalent of A$1.3 million if he is to go on and take the title.
Still feeling the effects of a virus, Stenson, who won here in 2008, ultimately signed for a 70, which kept him three clear of third-placed South African Jaco Van Zyl, who birdied the last for a level par 72.American Robert Streb also shot a 72 to lie fourth on nine under, two clear of Austrian Bernd Wiesberger and South African Branden Grace.
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