American Luke List is the first-round leader of the Scottish Open after a course record-equalling seven-under-par 63.
His compatriot Rickie Fowler and England's Lee Westwood among a group of five players lurking one stroke behind. The others are Robert Rock, Scott Fernandez and Jens Dantorp.
Fowler, the most recent winner at Gullane Golf Club in 2015, was the early clubhouse leader after his 64.
List, making only his seventh appearance on the European Tour, fired nine birdies and two bogeys on Thursday.
World No.3 Justin Rose, the highest-ranked player in the event that serves as a warm-up for next week's British Open at Carnoustie, carded a 67 while five times major champion Phil Mickelson was on level par after a 70
"I think this is probably the best preparation you can get," Fowler said.
"Carnoustie is probably a bit firmer and faster than here right now but this place could dry out over the weekend.
"It's great to be over here playing on similar ground, feeling how much the wind affects the ball, and just getting acclimatised."
Masters champion Patrick Reed was part of an eight-strong group in a tie for seventh after a 65.
Scott Hend is the leading Australian in a tie for 15th after an up and down round of four under 66, which included an eagle two and six birdies.,
His countryman Adam Bland (67) is a shot further back in the group with Rose while Wade Ormsby and Cameron Smith (both 68) are well placed to see weekend action.
On a day when almost 100 players broke par, Sam Brazel and Jason Scrivener both had rounds of 70 while Andrew Dodt (71), Brett Rumford (72) and Jason Norris (74) struggled.