Alexander Bjork and Scott Jamieson remained tied at the top of the leaderboard after 54 holes to set up a grandstand finish to the Tshwane Open for Sunday's final round.
The duo were locked at 10 under par after round two in Pretoria and remained level at 13 under following rounds of 68 in Saturday's third round.
Both needed birdies at the last to retain their share of the lead, though, having briefly shared top spot with Dean Burmester and Jorge Campillo.
Bjork - playing in only his ninth European Tour event - raced out of the blocks with birdies at the opening two holes and he picked up another at the seventh to give him a one-shot advantage at the turn.
That lead became two after another birdie at the 12th, but bogeys at 13 and 15 dropped him back into the pack before he kept his cool at the last with a four on the par five.
Jamieson's day started slower than his co-leader but he ensured parity with Bjork thanks to birdies at 12, 13 and 18 - the latter coming after a beautifully judged approach.
What a shot into 18 from Jamieson-- The European Tour (@EuropeanTour) March 4, 2017
He made birdie to tie the lead. pic.twitter.com/toUoduQFPK
Behind them Burmester recovered from a bogey at the first to card a 65 to move one behind, while Campillo's eagle at the last saw him join the South African in close contention.
Finland's Mikko Korhonen is a further shot adrift, while Oli Fisher surged 43 places with the first 62 in his career.
The 28-year-old had been steady on the opening two days but that all changed on Saturday with nine birdies, including the last three holes, to give him a surprise chance at the title on 10 under - where he is joined by four other players.