Dane Rasmus Hojgaard carded a brilliant course-record 62 to open up a three-shot lead heading into the final round of the Cazoo Classic, while Niall Kearney is best of the two remaining Irish at the tournament, sitting seven shots further back.
The 20-year-old Hojgaard has been a revelation since becoming the first player born in the 21st century to come through the European Tour's qualifying school in 2019, claiming two wins before the age of 20 in his rookie season.
He started the day at London Golf Club six shots off the lead but made 10 birdies in a bogey-free round to get to 14 under and lead the way from England's Jordan Smith and Scot Calum Hill.
Smith made five birdies in a row from the third on the front nine as he got to 14 under but he came home in 39 to sign for a 70.
There was no such wobble from Hojgaard, who made six birdies on the front nine to join the lead and four more coming home - including on the 17th and 18th - to take control.
"I didn't have any clue what the course record was," he said. "I knew I was probably around it but I didn't know what it was.
"I drove the ball way better today than I did in the first couple of days. So I was putting myself in position and I could be aggressive from the fairway, holed putts from everywhere basically and then I had a spell on the back nine where I was really stressed.
"We were on the clock so I probably rushed a couple of shots but then I finished strongly so I'm very happy."
Hill was bogey-free but managed just two birdies on the ninth and 13th in his 70 to sit a shot ahead of England's Richard Bland and Dale Whitnell.
Scottish pair David Drysdale and Richie Ramsay and Wales' Jamie Donaldson were then in the group at nine under alongside Ryder Cup hopeful Victor Perez and Dutchman Lars Van Meijel.
Dubliner Kearney is on seven under after a third-round 71, while Northern Ireland's Jonathan Caldwell is level par following a two-over 74.