Paul Dunne signed for a 66 to set the clubhouse target at nine under midway through the third round of the ISPS Handa World Super 6 Perth.
The top 24 after Saturday at Lake Karrinyup Country Club will qualify for Sunday's six hole match play knockout and just three shots separated the top 27.
There was also a battle going on at the very top of the leaderboard, with the top eight receiving a bye into the second round on day four.
Dunne put himself in pole position to move straight into the last 16 and sat a shot ahead of Yuta Ikeda, Matt Jager, Per Langfors, Gareth Paddison and Thomas Pieters.
Ryan Fox, Daniel Gale, Jazz Janewattananond, Min Woo Lee, Robert MacIntyre and Adrian Otaegui were then at seven under.
As things stood, 15 players were set to play off for the final 12 spots in the match play.
Pieters made the perfect start as he birdied the first for the third day in a row to break out of the leading pack, with playing partner MacIntyre also making a gain on the opening hole.
Langfors birdied the tenth and 11th and while he bogeyed the 13th, he eagled the short par four 14th and followed that with gains on the 15th and 16th.
Jager then made a birdie on the third to join the group one off the lead and he was soon in a share of top spot as Pieters double-bogeyed the third for the second time this week.
Fox bogeyed the second but bounced back from ten feet on the third.
Jager birdied the fifth to hit the front on his own but bogeyed the next and was replaced by Fox and Panuphol Pittayarat, who both birdied the fourth.
Another Langfors birdie on the first had him within one of the lead and Pieters joined him with a birdie on the fifth.
Otaegui had been in the battle for a top 24 spot after making two birdies and two bogeys in his first six holes but an eagle on the par five seventh moved him to eight under and gave him some breathing room.
Fox bogeyed the sixth to drop into a six-way tie for the lead as Pittayarat made a double, but they were soon all leapfrogged by Dunne.
The 26-year-old birdied the first and seventh but really came to life after the turn, making a gain on the 11th, draining a 50-footer for another on the 12th and then getting on the green at the short 14th for an eagle.
He came up just short of the par five next in two blows but two putts from off the green handed him a birdie and a two shot lead at ten under.
Otaegui and MacIntyre both dropped shots on the eighth, with Pieters making a birdie to edge into second place on his own.
Pittayarat dropped a shot on the same hole and followed it with another on the ninth to fall from a share of the overnight lead to the wrong side of the cut line.
Dunne then missed the green on the par three 17th to drop a shot and Pieters was back in a share of the lead.
A Pieters bogey on the tenth handed Dunne the solo lead once more and the Irishman parred the last.
Fox bogeyed the ninth but picked the shot straight back up as Ikeda and Paddison moved through the field.
Paddison sandwiched a bogey on the eighth with birdies on the third, fourth, fifth, 11th, 15th and 16th, while Ikeda had seven birdies and a bogey in 16 holes.