Daniel Hillier carded a stunning round of 62 to take a one shot lead into the weekend at the 2021 ISPS HANDA World Invitational presented by Modest! Golf Management.
The New Zealander is playing just his seventh European Tour event and arrived in Northern Ireland this week with no playing privileges on the European Tour or Challenge Tour.
But the 23-year-old made a mockery of that status, beating his lowest round on Tour by four shots at Galgorm Castle Golf Club to get to 11 under and lead the way from England's Jordan Smith, who carded a 68 at Massereene Golf Club.
Englishmen David Horsey and Garrick Porteous were at eight under, a shot clear of countryman Eddie Pepperell, Spanish duo Nacho Elvira and Carlos Pigem, and German Matthias Schmid.
In the women's event, American Emma Talley held a three shot lead over countrywoman Jennifer Kupcho and South Korea's Chella Choi at 13 under.
Hillier enjoyed an excellent amateur career, twice winning the New Zealand Amateur, representing his country at the Eisenhower Trophy and winning a professional event on his native Charles Tour.
Just six events were played on the Charles Tour in 2020 due to the Covid-19 pandemic but the 23-year-old won two of them and is playing this week on an invite.
"It was really good out there," he said. "Made the most of some pretty benign conditions in the morning and got off to a good start. Managed to sink a couple more near the end.
"I've hit it really well. Made one bad swing on hole 11 and made bogey there but apart from that it was really solid.
"I've been playing well the last couple of months, just haven't really put four rounds together yet. In a pretty good position at the moment so just going to keep riding the wave and stick to the game plan and see how we go."
The World Number 678 got up and down from the sand for a birdie on the par five tenth and while he gave the shot straight back on the next, he holed a 16 footer on the 13th and never looked back.
A tee shot to 11 feet on the 14th and approach to three feet at the next made it a hat-trick before a smart pitch on the 17th saw him turn in 32.
Impressive iron play on the first and second brought two more birdies and he holed a 20 footer on the fourth before another smart approach brought a ninth birdie of the day.
A plugged lie at the tenth saw overnight leader Smith open with a double bogey and while he clawed the shots back on the 12th and 16th, bogeys on the 18th and second saw him stumble before he made gains on the third, sixth, seventh and ninth.
Also playing Massereene, Horsey stayed bogey free for the week with birdies on the third, eighth, 12th, 16th and 17th in a 65, while Porteous carded a 64 with seven birdies and a single bogey.
Pigem carded a 63 with nine birdies at Galgorm Castle, with Pepperell signing for a 67 on the same layout after a bogey on the last.
Last week's winner Elvira recorded a 67 at Massereene, two shots better than Schmid who is playing just his second professional event.
Spaniard Alejandro Cañizares, Scotland's David Drysdale, South African Justin Harding, Japan's Masahiro Kawamura, Swede Vincent Norrman and English pair James Morrison and Jack Senior were at six under.
Talley has produced the performance of the week so far and birdied five of her last six holes in a 65 at Massereene.
"Confidence I think is the main thing," she said. "I think this is the first time in a long time that I've been in this position but it's the first time in a long time that I've felt this comfortable over the golf ball and with my putter. I feel really relaxed. There's a lot of golf left, so just going to stay patient and keep doing our thing."
Choi and Kupcho both carded rounds of 69 to sit at ten under, a shot ahead of Scot Gemma Dryburgh and England's Charley Hull.