Despite missing out on a sixth major title at the age of 46, Mickelson said he can take some consolation - quite a lot of satisfaction - from how he played.
Like two prizefighters in a boxing ring, the two men traded blow after stunning blow, reeling off birdie after birdie to turn the final day of golf's oldest Major into a two-way procession.
Stenson reached a career-high ranking of number two in the world in 2014, and said after his success at Royal Troon: "We're only just getting started, aren't we?"
Stenson's 72-hole total of 264 also eclipsed the previous best in a major set by David Toms in the 2001 US PGA and was three lower than the previous Open record set by Greg Norman at Sandwich in 1993.
The final major of the season, the US PGA Championship at Baltusrol in New Jersey, begins earlier than usual this year, starting on July 28.
It was a slight measure of revenge for Stenson, as he was runner-up to Mickelson in the 2013 Open at Muirfield.
Spare a thought for five-time major victor Mickelson, aiming to become the oldest victor of the Open in the modern era.
There is little doubt Mickelson felt unlucky with how well he played on the final day, with not a single bogey in his six-under-par round of 65.
Stenson had always been considered one of the best players on tour never to have won a major but he put that right in the most spectacular fashion at Royal Troon on Scotland's west coast.
Stenson held the claret jug and told Mickelson at the closing ceremony, "Thank you very much for a great fight". And after seeing the golf on display on this major championship Sunday, it was no case of recency bias or hyperbole, this was just as good. That definitely helped this week and I felt that extra confidence was going to be huge for me coming into this week. "So I just tried to do the same, and just delighted to come out on top and managed to win this trophy".
In scenes reminiscent of Tom Watson and Jack Nicklaus's epic Duel in the Sun shoot-out at Turnberry nearly 40 years ago, Stenson staved off the challenge of the 2013 champion Phil Mickelson on the Ayrshire coast with a sparking eight-under 63 for a record-busting 20-under 264 and a three stroke triumph.
With the drama building as each hole passed, Stenson broke away on the 14th and 15th holes, continuing one of the most unbelievable putting displays in a long time in a major championship.
Mickelson had his chances on the final few holes of the tournament. That brought the pair into a tie for the lead at -16.
This putt would have momentarily tied the score - Stenson would birdie a moment later - and Stenson seemed to know he had caught a break.
The turning point in the round was when Stenson sank a 50-foot birdie putt on 15 to take a two-shot lead.
Mickelson was trying to become the second-oldest British Open champion in history, and the oldest since Tom Morris in 1867. Sunday, Stenson made birdies on 14, 15, 16 and 18 and had two bogeys in the round.
"I knew that he would ultimately come through and win and I'm happy that he did". I'm disappointed that it was at my expense.
J.B. Holmes won the B-Flight.
"Those guys are playing a different golf course than everyone else", Holmes said.
Mickelson shot 17-under and lost to Henrik Stenson by three strokes - the lowest ever major total for a runner-up. No one older than 48 has won any major championship. Beyond the score, the measure of his performance was that he putted for a birdie on every hole Sunday in a mild wind off the Irish Sea. No one blinked. Stenson frankly knocked Mickelson out with three birdies in a row from the 14th.