Lee Westwood made the most of ideal conditions to fire a flawless 65 in pursuit of a second Scottish Open title, 23 years after the first.
Westwood carded six birdies at the Renaissance Club to sit a shot off the leader Jack Senior.
American Justin Thomas was also six under for his opening round, with a strong chasing pack including new US Open champion John Rahm, Tommy Fleetwood and Ian Poulter on five under.
“I think the longest par putt I holed was two feet, which shows I was never under any stress,” said Westwood, who previously won the title at Loch Lomond in 1998.
“I gave myself a lot of birdie chances. I did everything well in fact.”
Westwood practised at the Renaissance Club in the week before finishing 13th in last year’s US Open and had plenty of other experience of the venue to draw upon from the time he lived in Edinburgh.
“It always helps if you’ve played a course a lot, especially if conditions change,” the former world number one added.
“Today is not typical of golf here. It was pretty much hit it, find it, hit it again – you didn’t have to use your brain too much or get creative. It was a good day for scoring.”
Fleetwood carded seven birdies and two bogeys in his 66 as he bids to go one better than last year, when he lost a play-off to Aaron Rai after three-putting the first extra hole.
“I don’t think this tournament owes me one, I messed it up all on my own,” said Fleetwood, who was officially selected to represent Team GB in the Tokyo Olympics earlier this week.
Home favourite Bob McIntyre is four shots off the lead after a solid opening round of 68.
But Rory McIlroy had another frustrating afternoon after finishing in a tie for 59th at last week’s Irish Open.
The Northern Irishman carded four bogies in his round of 70, which was rescued by two birdies in the final three holes.
©️ Agence France-Presse