Colin Montgomerie believes Henrik Stenson produced one of the best displays in major history to win The Open at Royal Troon.
Stenson secured his first major in sensational style on Sunday, a magnificent 63 - featuring 10 birdies - carrying him to a record-breaking aggregate total of 20 under.
Phil Mickelson did his best to keep pace with Stenson in a thrilling duel, only to come up three strokes short as his rival picked up shots at four of the last five holes.
Former world number two Montgomerie, who was also part of last week's 156-man field on his home course, had nothing but admiration for the 40-year-old Swede's performance.
Speaking at the Berenberg Gary Player Invitational, Montgomerie told Omnisport: "That was one of the rounds of major golf.
"There's very few 63s been shot, never mind on the last day to win. To start one ahead and shoot 63 [is incredible]. You must feel sorry for Phil Mickelson.
"Phil definitely added to the drama of the day. But four birdies at the last five holes, and it should have been five if you include [a makeable chance at] 17, was quite phenomenal golf around a very, very tough course.
"To break The Open course record for 20 under par around Royal Troon, no-one ever thought was possible.
"So it was a fantastic performance from Henrik Stenson, one of the performances in major golf."
Stenson became the fourth successive first-time winner of a major, following in the footsteps of Jason Day, Danny Willett and Dustin Johnson.
Willett, who claimed a shock victory at the Masters in April, told Omnisport: "He'll be feeling very good today. He'll wake up and he'll wonder what's gone on and look over and see the Claret Jug and he'll realise it was not a dream.
"I think everyone on Tour you'll speak to will be delighted that Henrik's finally won a major. He's a fantastic player and has been for many, many years.
"The competition you saw yesterday; them two [Stenson and Mickelson] battling it out down the stretch was golf at its finest."