A bogey on the ninth from Zander Lombard meant there was a four-way tie for the lead as the Joburg Open reached its closing stages at Royal Johannesburg & Kensington Golf Club.
The 20 year old, who turns 21 on Monday, is looking to be the second South African in as many weeks to claim a maiden European Tour victory after Brandon Stone's win at The BMW SA Open hosted by City of Ekurhuleni.
Lombard has enjoyed an excellent start to the season, missing out on a play-off at the Australian PGA Championship by one shot and finishing in a tie for 12th last week at Glendower Golf Club.
He was making serene progress at two under for the day as he faced a 15-foot putt for birdie on the ninth but three putts meant he turned in 36 and dropped into a share of the lead at 16 under with Daniel Im, Haydn Porteous and Anthony Wall.
Both Im and Porteous are also seeking their first wins but for Wall it would be a second triumph, 16 years and one day after his first, and would set a new European Tour record of 415 events between wins.
There are also three places at The Open Championship up for grabs for the top three non-exempt players in the top ten, who are likely to be the top three with the closest exempt players in the clubhouse five shots off the lead.
Wall got off to an excellent start as he put his third shot on the par five first to within six feet and holed out for birdie with playing partner Im also making a gain.
Both men then hit close tee shots into the 251 yard par three second but saw their putts lip out as Lombard and Porteous both parred the first, with the latter making hard work of it after going left off the tee.
When Lombard put his tee shot left of the green on the second it looked like a shaky start was in the offing but the 20 year old holed his chip brilliantly to join Wall with Porteous making his par.
Challenge Tour graduate Björn Åkesson was making one of the big moves of the morning and an impressive bunker shot handed him a birdie at the sixth to add to gains at the first and second to move him to 14 under.
Another birdie at the seventh then moved him into a share of second place after Lombard and Porteous both parred the third and another gain on the eighth meant he was in a share of the lead.
A clumsy first putt on the ninth led to a bogey which dropped Åkesson into the group at 15 under where he was joined by Wall, who bogeyed the par three fifth.
Im took advantage of the par five sixth to also move to 15 under and Ross McGowan, who battled to a 73 on Saturday, made birdies on the sixth and eighth to expand the group one off the lead to five players.
They were soon two off the lead, however, as Lombard hit a brilliant second shot into the sixth and two putts were enough to get him to 17 under as Porteous made it six straight pars.
The par fives were proving a happy hunting ground for many of the players out there and Lombard's two-shot lead was short lived with Wall and Im both making birdies on the eighth.
Porteous played an impressive bunker shot on the same hole to record his first birdie of the day and get to 16 under while Lombard three-putted for par with the lead staying at one.
A second consecutive three-putt then dropped Lombard back into a share and set up a dramatic afternoon in Gauteng.
Åkesson remained at 15 under through 14 holes, a shot clear of McGowan who had bogeyed the tenth.
Johan Carlsson and Paul Dunne were then at 13 under, a shot clear of the South African group of Jacques Blaauw, Alex Haindl, Jean Hugo, Richard Sterne and Justin Walters.