The seemingly ageless Phil Mickelson hopes more major championship wins are to come after falling short in his valiant quest for more Masters glory.

The 52-year-old three-times champion graciously settled for a second runner-up finish - and a remarkable 10th top-10 at Augusta National - after enjoying the clubhouse lead for some two hours on Sunday's final day.

Spanish ace Jon Rahm eventually ran him down, but Mickelson was still suitably proud of his seven-under-par 65 after starting the final round 10 shots off the lead.

"It was a fun day," Mickelson said.

"You just never know what can happen. There was nine holes left to go when I walked off the golf course. I was two behind and Jon played an amazing back nine.

"I mean, a lot can happen on that back nine. A lot of good can happen and a lot of bad, and he played some incredible golf all week long, and is a very worthy champion.

"(It's) easy to see why he's regarded as the best player in the world, and he validated that today."

Rahm vaulted back to No.1 in the world rankings, leapfrogging 2022 Masters champion Scottie Scheffler and Rory McIlroy, with his second major win.

But Mickelson, who had been bidding to wipe Jack Nicklaus from a page in golf's record books by becoming the oldest Masters champion, believes he can still add to his five career majors.

"I'm hopeful that that's the case," he said after predicting before the final round he was about to "go on a tear".

"It was evident to me that I was hitting a lot of good shots, that I was playing well.

"Even after I might have had a mess-up here or there, I was able to stay present, keep hitting good shots.

"And I'm hopeful that this catapults me into playing the rest of the year the way I believe I'm playing."

In great news for Australian fans, Mickelson's next event is this month's LIV Golf Adelaide, where local hero and reigning British Open champion Cameron Smith, fellow Masters runner-up Brooks Koepka will also be among those teeing up at the Grange Golf Club from April 21-23.

"I really worked hard in the off-season to get ready," Mickelson said.

"I've been shooting some really low scores at home, and today I let it happen rather than trying to force it. I had a really good day and made some noise.

"Unfortunately it wasn't enough, but it was really a lot of fun for me to play at this level again and it's encouraging for me going forward for the rest of the year."