Anton Karlsson produced a stunning round of 63 on day one to put himself in pole position to claim the top seeding at the Belgian Knockout.
The top 32 from each side of the draw after 36 holes at Rinkven International Golf Club will make it through to the knockout stages and Karlsson's eight under total was the best of any player in the field by two shots.
The 64 players that advance from the first two days will be seeded based on their score regardless of which side of the draw they were in, and will then go head to head over six rounds of nine hole knockout stroke play to determine a winner.
Swede Karlsson has had two top tens since regaining his playing privileges at the 2018 Qualifying School to sit 111th on the Race to Dubai Rankings Presented by Rolex, but found his form in spectacular style in Antwerp.
Spaniard Gonzalo Fernandez-Castaño was the closest challenger in that side of the draw at six under, a shot clear of Italian Lorenzo Gagli, England's David Horsey, Scotland's Robert MacIntyre and South African Justin Walters.
Karlsson made five birdies in a row from the 13th to surge up the leaderboard and while he gave a shot back on the first, an approach to five feet at the fourth had him back at five under.
He then holed a monster putt on the par five fifth for eagle and another from similar range for a birdie on the next to jump clear.
"It was a great round of golf," he said. "I've been playing some good golf lately, not getting any scores together is what it's been feeling like but today it came together as a whole.
"My best day in a long while with the putter. It was tough for a while to actually miss a putt. During the back nine I kept rolling them in from wherever, really, which is always a nice feeling."
Fernandez-Castaño is a seven time European Tour winner but had to regain his card at the Qualifying School in 2017 and has played 13 events so far this season despite a heavy travel schedule with his family based in Florida.
Incredibly, he decided to drive the nine hour journey from last week's Made in Denmark presented by FREJA, but showed no ill effects as he birdied the third, fifth, sixth, eighth, 11th, 12th and 16th, with a single bogey on the ninth.
"We drove all the way from Aalborg," he said. "It took us just over nine hours but it was a lot of fun, especially driving around Germany where there are no speed limits.
"I'm feeling great. I've hit the ball really well today, I've manged to keep the ball in play most of the time. Having all these tree lined courses it's always about getting the ball in position and I think I did that very well.
"I'm looking forward to tomorrow and the weekend because it's a great course for the type of event and the format we're playing."
Gagli turned in 35 with a birdie on the sixth but caught fire on the back nine, making gains on the 12th, 13th, 14th and 16th, while Horsey was also bogey free with birdies on the 17th, first, fourth, fifth and ninth.
MacIntyre has finished second in his last two events and he maintained momentum with seven birdies and two bogeys.
Walters made eight birdies and three bogeys to also sit a shot ahead of defending champion Adrian Otaegui, Frenchman Adrien Saddier and Swede Sebastian Soderberg.
