Prom Meesawat signed for a 67 to finish top of the leaderboard after three days of stroke play at the ISPS HANDA World Super 6 Perth.
Play on Sunday will switch to match play, with five rounds of six hole knockout matches to determine who will win the second staging of this revolutionary event at Lake Karrinyup Country Club.
Thai Meesawat will have a bye into the last 16 after finishing at 12 under, two shots clear of Dane Thorbjørn Olesen, American Sean Crocker and Australian Lucas Herbert.
Englishman Sam Horsfield, Japan's Yisaku Miyazato, and Australians Brad Kennedy and Dimitrios Papadatos secured the other four first-round byes after finishing at eight under.
There was then a further eight players safely through to the Super 6, with nine players at five under going into a play-off for the final eight spots.
Meesawat birdied the third but gave the shot back on the next before birdieing the fifth from six feet.
He made a hat-trick of birdies from the tenth - including a monster putt on the 12th for the second day in a row - before dropping a shot on the 13th but further gains on the 15th and 17th took him clear.
"I did well for the last two days, I only missed a couple of shots to put myself in the top position," said Meesawat.
"Very happy to finish first but still a lot of golf for tomorrow and I think it's going to be good fun.
"It [a win] means a lot. I'm going to earn my European Tour card and it's going to be the first win for me on the European Tour.
"I'm just going to go out and have fun, concentrate with my game."
Very happy to finish first but still a lot of golf for tomorrow and I think it's going to be good fun - Prom Meesawat
Olesen - a winner here in 2014 - led by two at the turn after birdies on the first, third, seventh and eighth - courtesy of a huge putt.
He went bogey-birdie on the tenth and 11th before dropping shots on the 14th and15th and making a birdie from the fringe on the 17th.
Crocker signed for a 67 while Herbert, who was playing alongside Meesawat, joined Olesen in carding a 69.
Qualifying School winner Horsfield turned in 33 with birdies on the first, third and seventh and when he made a hat-trick from the ninth, he was tied for the lead.
A double-bogey on the next threatened to derail his chances but he birdied the 15th and was able to secure a seeding despite a bogey on the last.
Papadatos signed for a 66, Kennedy a 67 and Miyazato a 68 to secure their places in the top eight.
Australian Marcus Fraser and Scot Grant Forrest finished at seven under, a shot clear of Australians Nick Cullen, Ben Eccles, Matthew Millar and James Nitties, amateur Win Moo Lee and Thai Pavit Tangkamolprasert.
In the play-off, Italian Andrea Pavan, South Korean Yikeun Chang, Australian Callan O'Reilly and Thai Poom Saksansin all made par and had to wait to see what the next group up the 18th would do.
South African Zander Lombard, Australian Stephen Leaney and Japanese Satoshi Kodaira all also made par as those seven players secured their spots for Sunday, with Thai Kiradech Aphibarnrat and Australian Anthony Quayle making bogeys after failing to get up and down from bunkers.
Both players made par on the next trip - with Aphibarnrat having to get up and down from the front of the green - and then played the hole in almost identical fashion at the third attempt.
The duo ended up next to each other in front of the green after two shots at the next attempt and Aphibarnrat chipped to tap-in range and advanced to Sunday after Quayle failed to make par.