Greystones Paul Dunne fired seven birdies in a superb round of 65 to move into tied 17th at the Tshwane Open in South Africa.
Scotland's Scott Jamieson and Sweden's Alexander Bjork remain locked together at the top of the leaderboard heading into the final round.
The duo began day three tied for the lead and both carded rounds of 68 at Pretoria Country Club to reach 13 under par — a shot ahead of local favourite Dean Burmester and Spain's Jorge Campillo.
Dunne made the perfect start by birdieing the first and the second before dropping a shot at the sixth.
However, he stepped things up a gear from the ninth with a birdie there, followed by another at the 13th before finishing with a three in a row on the 16th, 17th and 18th.
Co-leader Jamieson has spent the last two seasons battling to retain his playing privileges, finishing 106th and 107th in the Race to Dubai, but won his sole European Tour title in South Africa at the rain-shortened Nelson Mandela Championship in 2013.
“I’m in a great position to go out and try and win the tournament (on Sunday),” the 33-year-old from Glasgow said after a round containing five birdies and two bogeys.
“Yet again I was really good tee to green but I felt as if I left quite a few out there on the greens. I wasn’t at my best there but (Sunday’s) another day and I have a chance of winning.”
Swedish rookie Bjork, who is playing in just his ninth European Tour event, birdied his first two holes to open up a two-shot advantage and also picked up shots on the seventh and 12th.
However, bogeys on the 13th and 15th allowed the chasing pack to close the gap, with Burmester making birdies on the 17th and 18th and Campillo doing even better with a birdie-birdie-eagle finish.
“I’m very pleased with my position,” Bjork said. “It was a solid round. I got off to a very good start with two straight birdies. Things were a little bit worse in the middle of the round but I finished with a good birdie on 18, so I’m looking forward to (Sunday).
“I’ve been in this position a few times on the Challenge Tour, but it’s bigger here — more people, more television and everything — so I’m interested to see how I handle it (on Sunday). It’s going to be a lot of fun to play.”
Oliver Fisher, who only made the halfway cut with a shot to spare, produced the round of the day with nine birdies and no bogeys in a superb 62, which lifted him 43 places up the leaderboard.