TROON, Scotland (AP) Now, Phil Mickelson knows how Jack Nicklaus felt that day at Turnberry.
Sometimes, you're just not good enough. Even when you play your best.
Mickelson turned in what would normally go down as one of the greatest closing rounds in major championship history - a bogey-free, 6-under 65 at Royal Troon.
Lefty was two shots better than anyone else in the field.
Except for one.
Henrik Stenson, in an epic match with Mickelson that rivaled the ''Duel in the Sun'' at Turnberry in 1977, made 10 birdies - 10! - on the way to a 63 that gave the Swede the first major title of his career and the lowest score in the history of the major championships.
Mickelson could only shake his head - he'll probably be doing that a lot in the days to come - as he pondered how Stenson snatched this one away.
''It's probably the best I've played and not won,'' Mickelson said, trying to figure out how a 17-under 267 finished three shots behind Stenson. ''That's probably why it's disappointing in that I don't have a point where I can look back and say, `I should have done that' or `Had I only done this.' I played a bogey-free round of 65 on the final round of a major. Usually that's good enough to do it. And I got beat. I got beat by 10 birdies.''
When the final group stepped to the first tee, the sun broke through the clouds for the first time in three days. That was fitting, as it rekindled memories of a sun-splashed day 39 years ago at another course in the British Open rotation, the one just 25 miles down the Scottish coastline.
In a shot-for-shot showdown between two of the game's greatest players, Tom Watson's 65 was just good enough to beat Nicklaus' 66. The next-closest finisher was 10 strokes behind.
''It certainly crossed my mind a little bit out there today, that match when Jack and Tom went head to head there in `77,'' Mickelson said. ''I know that I wanted to be more of Tom in this case than Jack, but I understand how it feels. It's bittersweet.''
This one followed much the same script. Stenson began the day with a one-stroke lead, a deficit Mickelson erased with a birdie at the very first hole. They went back and forth from there, pouring in birdie after birdie - and even an eagle from Lefty at No. 4.
Their games were so in sync that, at one hole, they had to consult on who was away. The margin never was more than a single stroke until the 15th hole. That's where Stenson finally gained the upper hand, rolling in a 50-foot birdie putt from off the green.
Mickelson's last gasp came at the par-5 16th, where a 30-foot eagle try brushed the left side of the cup and stopped, but didn't drop in. Stenson made a matching birdie, pulling off a nifty up-and-down from the thick grass left of the green.
Stenson finished it off with another birdie at the final hole, giving him the lowest score in major championship history. The two players gave each other a hug, then walked off the green with their arms around each other's shoulders, much as Nicklaus and Watson did on that day at Turnberry.
Mickelson gave Stenson's wife, Emma, a peck on the cheek, before fading away to let the champion have his moment.
Next on the leaderboard was J.B. Holmes, a staggering 11 shots behind the runner-up.
''It's disappointing to come in second, but I'm happy for Henrik,'' Mickelson said. ''I've always thought that he is one of the best ball strikers in the game and that major championships are perfectly suited for him. I knew that he would ultimately come through and win. I'm happy that he did. I'm disappointed that it was at my expense.''
At 46, Mickelson knows that his window for winning a sixth major title is beginning to close. As it was, he would've been the second-oldest champion in Open history. No one older than 48 has won any major championship.
''You know, it's not like I have decades left of opportunities to win majors, so each one means a lot to me,'' Mickelson said. ''I put in my best performance today. Played close to flawless golf and got beat.''
At least Lefty won't have long to lament his 11th runner-up finish in a major, which is second only to Nicklaus - there's that name again - with 19. The PGA Championship begins in less than two weeks at Baltusrol, where Mickelson won that title in 2005.
''We don't have a month to wait between majors is a good thing for me,'' Mickelson said. ''I'm excited where my game is at and where it's headed.
''But,'' he quickly added, ''I'm disappointed that it wasn't enough today.''
Follow Paul Newberry on Twitter at www.twitter.com/pnewberry1963. His work can be found at http://bigstory.ap.org/content/paul-newberry.