Shubhankar Sharma will take a commanding five-shot lead into the final round of the Joburg Open after firing a 65 on day three at Randpark Golf Club.
Swede Christofer Blomstrand had raised hopes of a 59 on his 26th birthday but had to settle for an excellent 62 to sit 15 under, as Sharma became the first player to be 20 under or better after 54 holes on the European Tour since Rory McIlroy at the 2015 Omega Dubai Desert Classic.
The Indian is playing just his tenth European Tour event but has made nine cuts and enjoyed a top ten at the UBS Hong Kong Open two weeks ago.
"I'm really happy," he said. "I wanted to play even though I shot a ten under yesterday and it is always difficult to follow up on a low round. I'm really proud of the way I played today.
"I'm very pleased that I came to the Joburg Open. I had my visa but it has been a very long season so I was contemplating if I wanted to come here. I'm really happy that I did!
"I want to stay within myself and play against my course. I have a good lead but you saw some low scores today. Anyone can shoot a seven or eight under par. I need to stay calm and hit the right shots.
"I don't want to change my strategy because I've played solid golf. There's nothing much to change. You can't play it safe because everything is in front of you. I'm going to be aggressive and won't hit any stupid shots."
As well as playing for the trophy this week, the top three finishers not already exempt will earn a place at next year's Open Championship at Carnoustie Golf Links, so there was plenty on the line for a congested chasing pack.
England's James Morrison and South African Erik van Rooyen were at 14 under, a shot clear of another Englishman in Marcus Armitage and Finn Tapio Pulkkanen.
Blomstrand made the big early move, carding an eagle on the fourth to go with birdies on the second, third, fifth, seventh and ninth to turn in 29 and move within two of overnight leader Pulkkanen.
I'm really proud of the way I played today - Shubhankar Sharma
He bogeyed the tenth but bounced straight back with a lengthy putt on the 11th before Sharma joined the lead. A birdie looked a long shot when he was well short of the green and in the rough in two on the second but he got up and down brilliantly on the par five.
Pulkkanen missed the green with his second into the third to drop his first shot of the week and when Sharma holed from three feet after a stunning approach, the lead was two shots.
Blomstrand took advantage of the par five 12th to sit two off the lead but that was soon three back as Sharma made the most of the fourth after getting on in two.
Qualifying School graduate Blomstrand hit a brilliant approach into the 13th to tap-in range but Sharma was not in the mood to be caught and a tee-shot to three feet on the par three fifth extended the lead back to three shots.
Blomstrand was relentless and when he got on the 14th in two and holed a 20-footer for eagle, he was 11 under for the day and talk of a 59 began to circulate around the course - although preferred lies would have denied him his place in the history books.
Three pars and a bogey on the last from Blomstrand, coupled with an approach to four feet on the ninth from Sharma, then put the 21 year old three shots ahead.
He birdied the par five 14th and when he put his tee-shot to ten feet and rolled home on the par three next, he was 20 under and led by five.
Morrison made a birdie-bogey start but after a gain on the fourth, he made four in five holes from the seventh. A dropped shot on the 16th threatened to take him out of contention but he birdied the last.
Qualifying School graduate Van Rooyen turned in level par but picked up shots on the 12th and 15th.
Pulkkanen followed that bogey on third with another on the fifth but chipped in on the seventh and added further gains on the 12th and 14th before finding the water on the 16th for a double-bogey.
Armitage signed for a 67 to sit two shots ahead of South Africans Oliver Bekker and Christiaan Bezuidenhout, English duo Steven Brown and Ross McGowan, and Dane Joachim B Hansen.
