Italy's Francesco Molinari shot a course-record 62 to lead the Scottish Open on 10-under par after round one.
He rolled in 10 birdies at the Castle Stuart links near Inverness to earn a two-shot lead over Alejandro Canizares.
English pair Andrew Marshall and Robert Coles join Irish duo Shane Lowry and Peter Lawrie in a share of sixth place on six-under after carding fine 66s.
World number one and defending champion Luke Donald also kept himself in contention with a solid round of 67.
In favourable conditions, Molinari made the early running and was never in much danger of being caught.
The 29-year-old continued his blistering run of form from last week's French Open, where he closed with a 64 to finish second.
It was enough to rival the tournament's previous best round, set by Paul Curry in 1992 when he shot 60 at the par-70 Gleneagles course.
Molinari said he was thinking of his brother and Ryder Cup colleague Edoardo, who won the Scottish Open title at Loch Lomond two years ago but is missing this year's event while he recovers from wrist surgery two weeks ago.
"It would be nice to do well this week for him as well - to cheer him up a little bit," said Francesco.
If he wins this weekend it would be only the second time in European Tour history that brothers have won the same event. Spaniards German and Antonio Garrido were Madrid Open champions in 1973 and 1977, respectively.
At 10-under through 15, Molinari was in with a chance of scoring the first sub-60 round in European Tour history, but could only par the final three holes.
"I know it's not going to last for ever," he said of his recent purple patch, "but I hope to keep this going a little bit longer - obviously next week [at The Open], but the next month or so is really big for Ryder Cup [qualification].
"That, probably more than The Open, is in my mind."
Starting at the 10th, Canizares began his round solidly but finished with six successive birdies for a magnificent 64, a score which would usually secure a handsome lead.
One shot further back are Frenchman Raphael Jacquelin - third in the French Open last week - and Dane Soren Kjeldsen.
Donald was flying as well until he bogeyed two of his final five holes for a 67, but there were some big names who would have been delighted with that start.
Ireland's Padraig Harrington returned a 69 and South Africa's Ernie Els a 70 that included four in a bunker for a double bogey seven at the long sixth.
Andrew Johnston's 69 included a hole-in-one on the 168-yard 11th that won the Englishman 168 bottles of champagne.
"I think I'm going to have to give quite a few away or I'll turn into an alcoholic," he said.
There was no such joy for late entry Phil Mickelson, who left his family on holiday in Rome because of his recent poor form.
The American felt the need to play another tournament before The Open, which starts at Royal Lytham & St Annes on 19 July, but could only manage a 73, the same score as Scotland's top-ranked player Paul Lawrie.
England's Paul Casey also struggled, finishing four over. His disappointing form followed a pair of 80s in Paris last weekend.
The former world number three has made only one cut since dislocating his shoulder while snowboarding in the United States on Christmas Eve.