Sweden's Fredrik Jacobson battled to a level-par 71 in near-perfect conditions to earn a one-shot lead after the Scottish Open's third round.
The 27-year-old, who was four clear overnight, offset three birdies with three dropped shots to finish at 11-under-par 202 at a sunny Loch Lomond.
Jacobson, whose five second-place finishes on the European Tour career are the most by a player yet to win, was two ahead with two holes to play but missed a par-putt from under four feet at the 205-yard 17th to slip back.
"I had a good chance to move away from the field but at least I'm still leading, which is a new experience for me," said the Swede.
"I was relieved to make my par putt at the last after missing from three and a half feet on 17."
Argentina's Eduardo Romero, who birdied the last two holes for a 65, was second at 10-under 203 with England's Justin Rose (68) and Australian Stephen Leaney (67) a further stroke back in a tie for third.
"I putted really well today, and yesterday also," said the 47-year-old Romero, who has five top-10 finishes from only 10 starts to lie 17th on the European order of merit.
"In fact, I've played well all year. My confidence is good and my game has been fantastic.
"I really want another win and I am going to be trying my best this year and the next before I retire and go to the U.S. Seniors Tour," added the moustachioed Argentinian who has won seven titles in Europe.
England's Warren Bennett had reeled off four successive birdies after the turn to move into a share of the lead with five holes to play.
Bennett, who began the day six strokes behind Jacobson, drew level with the Swede at 10-under when he collected his sixth birdie of the round at the 560-yard 13th.
But the 1999 Scottish PGA champion then lost ground, bogeying the 14th and the last for a 68 and a share of fifth at eight-under with New Zealand's Michael Campbell.
Campbell, who won last week's European Open despite dropping shots at the last four holes, was delighted with his third-round 66.
"Today was probably the best round I have played for the last two or three months," the 32-year-old said.
"My mindset is very confident and I feel comfortable with my swing -- all good things for tomorrow and for next week [the British Open at Muirfield]."
Earlier, Darren Clarke had chipped in for an eagle at the 345-yard 14th on his way to a five-under-par 66. The Tyroneman took full advantage of the conditions, also collecting five birdies and two bogeys to finish at four-under 209.
Although Clarke was upbeat after almost driving the green at the par-four 14th before holing his chip from 16 yards, he was annoyed that he had dropped a stroke at the 430-yard last.
"I've been making shots but not scoring and it seems to be happening on a regular basis at the moment," he said. "I've been getting very frustrated.
"But I'm very close to playing very well and it would be great if it could all come together for me at Muirfield next week."