And, annoyingly for Mickelson, it could have been even better.
The 50-year-old birdied six of his first 11 holes but bogeyed three of the last six to finish the day five-under par and two shots ahead of the chasing pack.
But despite the tough ending to his round — the wind caused havoc as it picked up later on — Mickelson described having “fun” out on the course.
He got informed midway through his post-round press conference that he was the leader thanks to Branden Grace’s double bogey, and he hopes he can hear a similar thing on Sunday.
“So, if you were to tell me that like Sunday night, I’d really enjoy that, but right now there’s a lot of work to do,” Mickelson said. “I’m not sure it’s going to stand today. We’ll see. But the fact is I’m heading into the weekend with an opportunity and I’m playing really well and I’m having a lot of fun doing it.”
If he is able to hold off his younger competitors, Mickelson would become the oldest winner of a major. Julius Boros holds that record, winning the 1968 PGA at age 48. Jack Nicklaus won his last major at 46.
It’s been eight years since Mickelson won his last major, the Open Championship in 2013.
He has claimed two PGA Tour victories since then, as well as two wins on the PGA Tour Champions in 2020.
And after lamenting some focus issues in previous weeks, Mickelson says it’s something he’s been “working” on.
“I’m just making more and more progress just by trying to elongate my focus,” he said. “I might try to play 36, 45 holes in a day and try to focus on each shot so that when I go out and play 18, it doesn’t feel like it’s that much.”
He added: “I might try to elongate the time that I end up meditating, but I’m trying to use my mind like a muscle and just expand it because as I’ve gotten older, it’s been more difficult for me to maintain a sharp focus, a good visualization and see the shot.”