Swede Joakim Lagergren will take a commanding six-shot lead into the final round of the Northern Ireland Open Challenge at Galgorm Castle.
One ahead overnight, Lagergren's 66 extended his lead to six over Dutchman Tim Sluiter, England's Max Orrin and South African Brandon Stone.
Jonathan Caldwell is the leading Northern Ireland player on six under - seven behind Lagergren - after a 69.
Lurgan man Gareth Shaw is a further shot back on five under after his 69.
Both Northern Irishman are within three shots of second spot but the tournament now very much looks like Lagergren's to lose after the Swede produced an admirably composed round on Saturday.
Englishman Steven Brown caught Lagergren, 22, with a second-hole birdie but four birdies in six holes from the fourth then put the Stockholm native three ahead by the turn.
Lagergren, who hit a course record 62 on Thursday, wobbled as he bogeyed the long 10th and difficult par-four 11th but birdies at the 12th and 15th had the 22-year-back back in firm control.
Chasing his first Challenge Tour triumph, Lagergren picked up a further shot at the last for good measure to extend his lead to six.
Brown dropped out of second spot as he suffered three back-nine bogeys and now shares fifth spot with his fellow Englishman Charlie Ford, Welshman Rhys Davies and France's Adrien Bernadet.
World number 957 Lagergren's best Challenge Tour finish this year is a share of 19th at the St Omer event in France in June although he did make the cut at last week's Czech Masters on the main tour when he eventually finished 81st after disappointing closing rounds of 76 and 79.
Lagergreen finished 86th in the Challenge Tour rankings in 2011 but played mostly on the main tour in 2012 and 2013 as he achieved 140th and 144th positions in the Race to Dubai.
His best career-finish on the Challenge Tour is a sixth place at the 2011 Norwegian Challenge but he will considerably improve on that if he holds his nerve in Ballymena on Sunday.
Caldwell regrouped well from two dropped shots in his opening six holes to fire a two-under-par round which leaves him in a six-way tie for ninth spot.
Shaw is a further shot back on five under, tied for 16th spot but was left rueing a bogey at the closing hole after he was forced to take a penalty drop.
Ballymena amateur Dermot McElroy's hopes of emulating his top-10 finish from last year evaporated as he carded a 74 to drop to two over while Irish Close Champion John Ross Galbraith is two shots further back after a 75 on Saturday.
Italy's Niccolo Quintarelli produced the round of the day with a seven-under 64 which moved him up from the cut line of two over to sharing 16th with Shaw.
Three-time European Tour winner Johan Edfors is tied for 36th spot going into the final round after firing a 69 on Saturday.
On Friday, tournament ambassador Michael Hoey missed for the cut in the event for the second successive year after a 75 left him on four over.