England's Sam Hutsby, playing just his third European Tour event as a professional, was battling for the third round lead at the CASTELLÓ MASTERS Costa Azahar in Spain.
The 20 year old from Hampshire, runner-up to Italian teenager Matteo Mannasero in the British Amateur in June, was 13 under par after eight holes and sharing top spot with Swede Michael Jonzon.
Halfway leaders Martin Kaymer and Robert Allenby had both slipped back.
German Kaymer, playing his first event since breaking toes in a go-kart crash in August, was 11 under, while Australian Allenby was on the same mark after running up a double bogey six at the seventh.
Still looking dangerous, though, was defending champion Sergio Garcia. Playing on his home course the World Number Ten was one behind after seven holes along with Swede Peter Hanson.
Hutsby switched ranks after the Walker Cup last month. Playing on invitations and hoping to emulate Rory McIlroy two years ago by earning enough to avoid the Qualifying School, he then missed the cut in the Alfred Dunhill Links and Madrid Masters.
But this week has been a different story. Hutsby opened with a 65 and by adding a 68 was in eighth place after 36 holes.
Then came a hat-trick of birdies from the second and after bogeying the short sixth more birdies came on the next two holes.
Ryder Cup Captain Colin Montgomerie had been looking to climb into contention when he finished off his second round at the start of day, but double-bogeyed the 16th and 17th to drop nine adrift.
However, Montgomerie then played the first ten holes of his third round in six under to burst into a tie for 15th on nine under, only four back.
Jonzon and Hutsby both moved to 14 under early on the back nine, but Garcia joined them by picking up further shots on the ninth and 11th.
Kaymer and Sweden's Christian Nilsson - like Jonzon fighting to save his European Tour card - were one behind, while Montgomerie closed with another birdie for a 64 that was his lowest round since his last victory at the 2007 European Open.
"I've gone back to a short putter and have started to putt better," he said.
"But this year has been a complete and utter...one to write off. I've got to go and get my game sorted out."
He has not had a top ten finish since June last year, but he was in a tie for ninth.