Tyler Koivisto has a three-shot lead going into the final round of the Northern Ireland Open
US player Tyler Koivisto is on course to win his debut European Challenge Tour event after an eight-under 62 gave him a three-shot lead in the Northern Ireland Open at Galgorm Castle.
The Minnesotan, 27, is three clear of Spain's Santiago Tarrio and England's Andrew Wilson going into the final day.
However, Koivisto, on 10 under, still has work to do with the top 15 all within six shots of the lead.
These include leading Irishman JR Galbraith whose 66 left him four under.
Five foot eight inch Koivisto's method relies more on a tidy shot game than the power golf so prevalent in the current era.
The American's opening nine holes on Saturday didn't hint at the heroics to follow as he reached the turn in two-under-par 32 after birdies at the second and seventh.
Koivisto cuts loose on back nine
However, he cut loose on the back nine as a further gain at the 10th was followed by four straight birdies from the 13th before he completed his blemish-free card with a four at the par-five last.
Koivisto was on a golf scholarship at St Cloud State University during his collegiate days before beginning a teaching career in the US.
However, he gave up teaching his fourth graders two years ago to pursue a career as a golfer and operated largely on mini tours in the US before exploring the notion of coming to Europe last year.
"I did Q-School last year in Austria, so that gave me the opportunity here. I'm just trying to grind away," said the 27-year-old.
Darlington man Wilson, a former English amateur international, also went low on Saturday as his 64 included an eagle three at the 10th.
Wilson, 26, produced something of a breakthrough last year when he won on the third-tier EuroPro circuit and also qualified for the Open Championship at Royal Portrush where he eventually finished in a share of 32nd spot.
The Englishman is joined on seven under by 29-year-old Spaniard Tarrio while an international-looking leaderboard has Switzerland's Benjamin Rusch, Norway's Kristian Krogh Johannessen, Belgium's Christopher Mivis and Iceland's Gudmundur Kristjansson a further stroke back.
Whitehead man JR Galbraith is six off the pace after a third-round 66
Those five off the pace include English duo Richard Mansell and Robert Dinwiddie plus Italy's overnight leader Enrico Di Nitto, who could only manage a 71.
After responding to an opening 75 with a superb 63 on Friday, Mansell's hopes of the title looked over after he took a triple-bogey seven at the first on Saturday but he regrouped with six birdies to post a 67.
Whitehead player Galbraith's only dropped shot in his 66 came at the third as he fired five birdies to move within touching distance of the leaders.
"My game was very solid tee to green and gave myself loads of (birdie) chances. I actually hit the hole and it bounced out with my second on the 16th," said the 26-year-old, who managed to hole his subsequent 10 footer for birdie.
Of the other Irish, Niall Kearney is tied for 23rd spot after a 68 moved him to one under par but Conor O'Rourke had a day to forget as a 79 saw him tumble down the leaderboard to joint last of the weekend qualifiers on eight over.
The European Challenge Tour event, which is being supported by the R&A, is the first of two big events at the Galgorm Spa & Golf Resort venue in Ballymena with the Irish Open being staged there from 24-27 September.
