Emiliano Grillo said his putter was the key to a third round 62 which put him two shots clear in the Africa Open.
The 21-year-old, ninth and 10th in this event in the last two years, carded nine birdies and no bogeys on the par 71 and said: "It was a good round of golf.
"I played well, but it was the putting that helped the most. I made some good ones on the back nine that kept my round going. I didn't hit it as close as I would have liked for nine-under, but I made them from all over.
"I played good for the whole round and I am quite happy with my game, so hopefully I can repeat it tomorrow.
"When you start making a couple of pars in a row you get impatient, so the key around here is waiting for the birdies.
"It's definitely more difficult than the past two days. The wind picked up and it was a little different direction to what we have seen, but I played good enough to not care about the wind today. Hopefully we will have similar conditions tomorrow.
Felt like a win
Grillo will be hoping to go one better than the second place he took in the recent Dubai Desert Classic won by Scotland's Stephen Gallacher.
Looking back to that runners-up finish which saw him produce an outrageous eagle on the 72nd hole when he holed from 60ft across the green, Grillo said: "I thought I had it for a moment (in Dubai) but Stephen played great on the last few holes so he got the trophy and I got second place, but it felt like a win for me.
"A great putt on the last hole gave me a lot of confidence for the rest of the year," Grillo told reporters.
England's Ollie Fisher, the 2011 Czech Open winner, is Grillo's nearest challenger on 18-under.
Fisher finished birdie-eagle-par-birdie to end just two back and said: "You had to be aware of where you were placing your ball with this wind, but it was good fun out there.
"I hit a few poor shots, but I'm delighted with the way I finished and pleased with my score for today. I'm two behind and it's the sort of course where guys can come from a long way back," said Fisher, who lost his card at the end of last season but would secure an effective three-year exemption with victory on Sunday.