Veteran American golfer Phil Mickelson has taken early command of the British Open with a spectacular record-equalling first-round 63 at Royal Troon.
The 2013 Open winner lipped out for birdie on the final hole just as he seemed poised to record the lowest round in major championship history.
Mickelson's sizzling eight-under display was still a course record and matched the best-ever score at a British Open.
The 46-year-old received congratulations from playing partners Lee Westwood and Ernie Els but was still shaking his head as he made his way to the scorers' hut.
"That was one of the best rounds I've ever played yet I want to shed a tear now," 2013 British Open winner Mickelson told reporters after his eight-under 63 left him three strokes clear of the field.
"That putt was an opportunity to do something historic. With a foot to go I thought I had done it."
"I saw that ball rolling right in the centre, I went to go and get it, I had that surge of adrenaline that I had just shot a 62 and then I had the heartbreak that I didn't."
Mickelson's effort was the 28th round of 63 in major history. The first one was posted by fellow American Johnny Miller in the 1973 US Open at Oakmont.
The five-times major champion enjoys a three-stroke advantage over countryman Patrick Reed, with fellow Americans Justin Thomas, Steve Stricker, Tony Finau and Billy Horschel among a bunch of players a further shot back.
Englishman Andy Sullivan and Soren Kjeldsen also carded 67s, but the day undoubtedly belonged to Mickelson, who was flawless in his eight-birdie round.
The back nine at Troon is one of the toughest homeward stretches on the Open rota, but the flamboyant left-hander made a mockery of its beastly reputation with just 31 shots after the turn.
Reed had birdied the last hole to seize the early clubhouse lead as Americans once again dominate the Open at Troon.
Aided by a hole-out eagle from the third fairway, Reed led for most of the afternoon.
Americans have provided the past six Open winners at Troon, stretching back to Arnold Palmer in 1962 and are once again threatening to continue the 54-year streak.
Mickelson's brilliance has left Jason Day facing a mountain to climb to work his way back into the tournament after Australia's world No.1 disappointed with a two-over 73.