He found fairways with his driver off the tee, made most of the putts he needed to, avoided any serious trouble, and for a while during his early-morning round led the field — much as he had done in 2008 and 2009 when he won this event.
It wasn't a perfect round. He started by lobbing a 15-yard shot into a bunker protecting the green on his first hole and finished the day with a bogey, but in between he did enough good things to wrap up a four-under-par 67, three off the lead.
"I just played well," Mickelson said. "I had a chance to go low, but I also had a lot of good breaks, so this was a good start."
Mickelson has won 42 events in his career but at 46, it's unlikely he'll dramatically improve on that total. His last win came in the 2013 British Open at Muirfield. Thursday, he showed many of the traits that have made him one of the world's most popular players and a few of the ones that have made him one of the most successful.
On the 596-yard 17th hole — his eighth after starting on the back nine — he split the fairway with his tee shot and hit a 319-yard three-wood just left of the green. Mickelson, whose aggressive style has led to a few failures as well as his many success, is never dull on the course, and that's been a large part of his attraction for fans.
"I was just trying to get up and down for birdie," he said. "but I hit a good chip and it just popped in the hole" for an eagle.
He wasn't as fortunate on his first hole, the 306-yard 10th, though he managed to salvage things. He hit his drive too far to the right, just short of the green, and faced a very difficult chip shot over a bunker to a green that sloped away from him. He took the customary full swing he uses on such lob shots but hit it about 18 inches short of where he wanted, and the ball trickled back into the bunker. His sand shot rolled just off the green, but he made the 10-foot putt coming back.
"It was nice to start with a par there when it could have been a lot worse," he said. "It's a very tough shot; I just put myself in the wrong spot."
His 10-foot downhill birdie putt on No. 11 lipped out, but on No. 12 he got the first of his five birdies with a 14-foot putt.
After Mickelson signed his card, he spent several minutes signing autographs for the people gathered around him near the clubhouse … except for one young fan who offered a ball to sign.
"I'm sorry," he told the fan. "I've signed golf balls for my kids, and those are the only balls I'll sign."