Phil Mickelson still feels as young as ever. He still plays that way, too.
Mickelson began his 27th full season as a pro Thursday by flirting with one of the few feats he hasn’t accomplished — golf’s magic number. The 48-year-old lefthander still shot a 12-under-par 60 in the Desert Classic, tying his career-low score he last shot in the Phoenix Open six years ago. It was the most under par he has been in any of the 2,077 rounds he has played on the PGA Tour.
‘‘It was a kind of a lucky day for me in the sense that I did not feel sharp heading in,’’ Mickelson said. ‘‘I haven’t really had the intense practice sessions that I would like, but I felt like all parts were OK and it just clicked. “Some days you have those days where it just clicked. And the bad shots that I hit, I got away with. I was able to kind of not have the big score.’’
Needing to play the final two holes in 2 under to shoot 59 on the foggy, rainy day at La Quinta Country Club, Mickelson missed a 15-foot birdie try on the par-4 17th before holing a 9-footer for birdie on the par-4 18th.
The Desert Classic is the only PGA Tour event to yield two sub-60 rounds. David Duval had a 59 at PGA West’s Palmer Course when he won in 1999. Adam Hadwin shot 59 at La Quinta in 2017.
‘‘I was aware of it,’’ Mickelson said. ‘‘I was giving it all I had and I had a good chance.’’
“On 17, I hit a nice tee shot in a good spot to kind of hook a sand wedge into that back right pin for me. And I hit a good shot, I had 18 feet though, I should have hit that closer, but still had a good chance to make the putt. Made a good birdie on 18. That’s not an easy hole for me, that shot the way it sits along the water.’’
Mickelson had a three-stroke lead over Adam Long, the 31-year-old PGA Tour rookie who finished off a 63 in the dark on PGA West’s Nicklaus Tournament Course.
The fog-delayed round was Mickelson’s first on tour since early October and the first in competition since beating Tiger Woods in Las Vegas in November in a made-for-TV event.
‘‘I knew it wasn’t far off, but it didn’t feel like I was ready to go,’’ Mickelson said. ‘‘I just felt like I needed to be careful. I felt I played a little bit more conservative.’’
Lefty birdied the first two holes and played the back-to-back par 5s in 3 under with a birdie on No. 5 and a 5-foot eagle putt on No. 6. He added a birdie on the par-4 ninth for a front-nine 30, and birdied the par-4 10th , par-5 11th, par-5 13th and par-4 14th, holing a chip from in front of the 14th green.
‘‘That was an interesting shot because I could have easily lost one and I ended up picking one up,’’ he said.
He then ran in a 5-footer for birdie on the par-4 16th.
The tournament winner in 2002 and 2004, Mickelson will play the Nicklaus Course on Friday and PGA West’s adjacent Stadium Course — also the site of the final round — on Saturday.
He won the World Golf Championships-Mexico Championship last year for his 43rd PGA Tour title and first since the 2013 British Open.
Long eagled the par-5 fourth and had seven birdies — five in a row from Nos. 9-13 — in an eight-hole stretch.
‘‘I just kept hitting it pretty close and making some good rolls and they were going in,’’ Long said. ‘‘I just kept feeding off it and tried to keep the pedal down.’’
Australia’s Curtis Luck was third at 64, also playing La Quinta.
Hadwin was at 65 with Trey Mullinax, Wyndham Clark and Martin Laird. Hadwin played the Stadium Course, Mullinax and Laird opened on the Nicklaus layout, and Clark was at La Quinta.
Defending champion Jon Rahm shot a 66 at La Quinta. He’s fighting a lingering flu bug.
‘‘Still pretty weak, which is possibly why I wasn’t hitting it quite as far,’’ Rahm said. ‘‘Not fully recuperated. My body is not a hundred percent.’’
Top-ranked Justin Rose had a 68 at La Quinta in his first start of the year. He’s the first No. 1 player to play the tournament since the world ranking began in 1986.
‘‘It’s kind of like you’re at the starting line and they kept dragging it back 30 minutes with the fog,’’ Rose said. ‘‘So, that was tricky just to keep warm really and keep loose. But once I got going I felt like I played really well.’’
LPGA — No one was entirely sure what to expect from the first LPGA Tour event of the year — least of all Stacy Lewis.
Nearly three months after Lewis became a mother, and six months after she last played on tour, she opened with seven birdies for a 5-under 66 that left her one shot behind Brooke Henderson and Eun-Hee Ji at the Diamond Resorts Tournament of Champions at Lake Buena Vista, Fla.
‘‘Pleasantly surprised,’’ Lewis said. ‘‘Had pretty low expectations going into the day. Just really made a lot of putts. I had some weird shots, which I knew was going to happen having not played in a while. I don’t know where it came from, but I'm going to take it.’’
Henderson overcame a slow start with a bogey on the second hole and a par save on No. 3 at the Tranquilo Golf Club at Four Seasons. She birdied five of her last eight holes for a 65 to tie Ji. , who had a bogey-free round.
The tournament — the first season-opener in Florida for the LPGA since 2015 — is only for LPGA winners each of the last two years.
Ariya Jutanugarn, coming off a year in which she claimed every major award, opened with a 67.
The event had the feel of a pro-am because of all the celebrities and athletes, although it wasn’t all hits and giggles. Along with the 26-player field from the LPGA Tour competing for a $1.2 million purse, 49 entertainers are competing for a $500,000 prize fund using the modified Stableford scoring system.
Tennis player Mardy Fish led that field with 39 points for a two-point lead over a group that included retired pitcher Mark Mulder.
But it was a different vibe from most LPGA events.
‘‘I had to remind myself it wasn’t Wednesday afternoon, it was Thursday, and I had to get a good score together,’’ Henderson said. ‘‘I think that’s when things kicked in on the front nine. I started getting a couple of birdies to recover from that bogey, and then from there I was ready to go and made a lot of birdies.’’
Lydia Ko joined Lewis at 66. Both formerly were No. 1 in the world.
Another shot back were Jutanugarn, Lexi Thompson and Mirim Lee.
Jutanugarn started the year with a new caddie, who previously worked for his fiancee, ANA Inspiration winner Pernilla Lindeberg. She opened with a 77, the highest score among LPGA players.
The Thai said she had some nerves from not having played in two months. And not being used to celebrities in her group also required an adjustment.
‘‘Because I didn’t play for so long — especially playing with them — I feel upset. He hit like 60 yards past me,’’ said Jutanugarn, who played in the same group with retired baseball players Josh Beckett and Kevin Millar. ‘‘Every hole he has a chance to make eagle, so I thought, ‘Maybe I'm not that good.'’’
She was referring to Beckett on the long tee shots. She didn’t know much about either, though she figured one thing one quickly.
‘‘I know they are baseball players. I know both of them are really famous,’’ she said. ‘‘And nobody asked me for an autograph. They all asked them.’’
Lewis had not played on the LPGA Tour since a 66 to tie for 39th on July 12 at the Marathon Classic in Ohio. She gave birth to her first child, a daughter they named Chesnee, on Oct. 25.
The biggest difference was her routine.
She now has to remember where to find daycare, to get out the door a little earlier and making sure she has all the bags for her game and her daughter.
‘‘You've got to take three trips to the care to get out the door every morning,’’ she said. ‘‘So it’s a new normal.’’
Her game looked like the old Stacy Lewis, at least for the opening round. She was 1 under at the turn until rolling in five birdies to offset one bogey on the back nine.
European — Shane Lowry recovered from two early bogeys by hitting enough good shots for a 2-under 70, giving him a one-shot lead going into the weekend at the Abu Dhabi Championship.
Louis Oosthuizen and Richard Sterne of South Africa each shot 68 and were one shot behind.
Three-time major champion Brooks Koepka, who has a chance to return to No. 1 in the world this week, bogeyed the 18th hole for a 70 and was five shots behind. Dustin Johnson had a 71 and was eight shots behind.
Another shot back was Tommy Fleetwood, who is going for a third straight title in Abu Dhabi.