Belgium's Thomas Pieters, the world number 690, produced a storming finish to his second round to claim the halfway lead in the Spanish Open at PGA Catalunya on Friday.
Pieters was two over par for the day after 10 holes, but birdied five of the next seven to come home in 31 for a second successive 69, despite playing in the windier afternoon conditions.
That gave the 6ft 5in 22-year-old, who secured his European Tour card via the qualifying school on the same course in November, a six under par halfway total and one-shot lead over Holland's Joost Luiten and England's Eddie Pepperell.
Luiten had earlier shrugged off a warning for slow play to card a 69 and join Pepperell on five under par, a target which did not look like being beaten until Pieters' late charge.
The group of Luiten, Miguel Angel Jimenez and Francesco Molinari were put on the clock by tournament officials after falling out of position, with Luiten given a first "bad time" for taking too long on his second shot to the seventh.
A second transgression would have meant a one-shot penalty, but the Ryder Cup hopeful went on to birdie the 542-yard par five and picked up another shot on the ninth, his final hole.
"I didn't know we were on the clock for two holes to start with and then she (an R&A rules official) came up and said you had a bad time," Luiten told Sky Sports.
"Someone was talking so I had to step out of the shot. It was only one bad time so I knew I could not do it again but I made a nice birdie at the end of that hole so it was okay.
"You have your routine and if you don't have to step out of the shot you are in time so I didn't really worry about it too much."
Gareth Maybin is the best of the Irish on one-under after a round of 70 with Paul McGinley, the European Ryder Cup captain, on level par after a second successive 72.
Shane Lowry has also made the cut despite finishing on two over.
Pepperell had carded an opening 68 to claim a one-shot lead overnight and was five shots clear of the field when, after starting on the back nine, he birdied the 10th and 11th and eagled the 12th.
However, he then ran up a double-bogey six on the 14th and bogeyed the 18th to be out in 35, with two birdies and two bogeys on the front nine meaning the 23-year-old from Oxford had to settle for a 71.
"The game's been pretty good for two days and five under puts me in a really nice spot for the weekend," said Pepperell, who finished 76th on the Race to Dubai in his rookie season last year.
"I expect to be caught today but I'm not too worried, if I keep doing what I'm doing I hope to have a shot at it come Sunday afternoon.
"It was a great start and I hit some really nice shots early. I had three 10-footers for birdie, birdie and eagle and I holed them all. But it was an up and down day for me. I hit some good shots in the early part of the round, but there were also some poor ones.
"Unfortunately, I made a double bogey where I played aggressively and it didn't come off. I didn't get the pace of the greens and had a couple of three putts when I bombed my first past the hole."
Molinari was two shots off the lead after six birdies and one bogey gave him a round of 67, with England's Richard Bland, Spain's Alvaro Quiros and Scotland's Richie Ramsay another stroke back on three under.
Pre-tournament favourite Sergio Garcia is one under after struggling to a 74.