Darren Clarke opened up a three-stroke lead after carding seven birdies in a six-under-par 65 in the second round of the Scottish Open.
The 37-year-old finished 11-under on 131, three ahead of South African Charl Schwartzel, Swede Johan Edfors and compatriot Damien McGrane.
Clarke has not finished higher than third in Europe this season, a result he achieved at the Irish Open in May.
The Irishman played flawlessly on the front nine, picking up birdies at the third, sixth and ninth in ideal scoring conditions.
Clarke made amends for a dropped shot at the 11th by birdying the 10th, 14th, 15th and 17th.
'I hit it really nicely today and gave myself an awful lot of (birdie) chances,' he told reporters.
'I had a lot of putts from the 10 to 12 feet range for birdies and unfortunately missed a few. But, overall, six-under is pretty good.'
Earlier, Schwartzel maintained a South African tradition for excellence at this event.
The 21-year-old raced home in 30 shots to fire a 66 in the final tournament in Europe ahead of next week's British Open at Hoylake.
Schwartzel, the second youngest South African to earn full membership of the European Tour after Dale Hayes, began his round in sedate fashion before his putter caught fire and he birdied the 12th, 13th, 15th, 17th and 18th.
Edfors, tied for the lead with David Drysdale overnight, had five birdies and three bogeys in his 69. McGrane returned a 66.
