Fleetwood birdied six of his last nine holes in an inward half of 30, just one shot outside the tournament record, to share the lead with American Keegan Bradley.
The pair sit a shot ahead of Korea’s Ben An and American Brian Harman, with Rory McIlroy was a stroke further back after a bogey-free 67. Tiger Woods mixed six birdies with four bogeys as he opened with a 70, the same as Scottish No 1 Russell Knox but Martin Laird is well down the leaderboard after a 76.
Fleetwood started from the 10th and managed just one birdie in his first nine holes, but then picked up shots on the first, second and fifth and finished with a hat-trick of birdies from the seventh.
“I played really well all day apart from I hit a poor tee shot on 14 and got away with it,” Fleetwood told Sky Sports. “And then on 16, the par-5, I hit a poor second and I was a bit frustrated at that point because I had a lot of chances from 15 feet and didn’t make any. It just shows you, stay patient and things can happen.
“The course doesn’t make you feel very comfortable at all, you are always a semi-bad shot from struggling to make par. It’s one of the courses that’s the ultimate test in golf.
“I’ve played well here in the past and if I drive it well that’s a massive key for me. Driving is a strength for me normally and if you put it in play all the time in general you have a big advantage.”
Fleetwood finished seventh at Sawgrass last year and third in the Arnold Palmer Invitational on Sunday, when Molinari stormed through the field with a closing 64 to win his second PGA Tour title.
“I’m trying to keep up,” Fleetwood joked. “It’s hard these days but I’m trying my best. It’s clearly the next step for me to win over here but winning’s not easy and I’ve got to keep plodding away, do the right things and focus on myself.
“It’s a good time to be coming into form. It’s been different this year because I’ve been used to starting so fast, but I feel like I’ve been doing a lot of good things and sometimes you just need a rhythm of shooting good scores and that seems like it’s coming.”
McIlroy was frustrated not to birdie the par-5 ninth, his final hole, after his approach hit a sprinkler head and flew over the green into the crowd. But his opening 67 left him just two shots behind Fleetwood and happy that the change in date from May to March meant the conditions were more conducive to aggressive play.
“Over the last 10 years it’s been irons off tees and really trying to plot your way around the golf course, I hit drivers on holes today where I would never have the last few years,” said McIlroy, who has finished in the top six in all five starts in 2019.
“Even when you are aggressive and you miss, it’s a touch easier to get yourself back into position. The rough isn’t as long or as gnarly and when you miss the greens you are not having to contend with that Bermuda [grass].”