He had four birdies in the first six holes and three more after the turn.
Rory McIlroy, Rickie Fowler, and Brooks Koepka will headline the star-studded field at the Arnold Palmer Invitational at the famed Bay Hill Club and Lodge in Orlando this week to pay tribute to the late golf legend.
Cameras caught the moment when Hatton looked at his caddie and said, "Have you seen a worse golf shot?"
Jason Day, the 2016 Bay Hill victor, withdrew injured on day one with a back issue.
"Apart from (the fourth through sixth holes) I actually played quite well today", Leishman said. "It's exciting, I've put myself in a good position, so I'm looking forward to it".
Former world No.1 and 2016 victor at Bay Hill, Day walked off after just six holes before revealing he had an MRI on Monday that indicated an annular tear in his L4/L5 disc.
The Australian world No.18 hit just 11 of 18 greens in regulation, but managed to negotiate the notoriously hard thick rough and fast putting surfaces at Bay Hill to sign for a two-under-par 70.
Mickelson's double-bogey came at the expense of one of the more daring shots of the day as the five-time major victor attempted a right-handed effort behind a net.
One killed, 33 wounded in blast inside bus station in Kashmir
Inspector General of Police, Jammu , MK Sinha, as quoted by PTI, informed that there was no specific input about such an attack. He also pointed out that he spotted 10 people injured at the scene who were being shifted to the nearby hospital by the locals.
"This is my first time playing Bay Hill, but I've watched the tournament on TV and I know how tough the course is", said Cabrera Bello, who has won six times as a pro but never on the PGA Tour.
The 29-year-old has risen to world No.6, helped by a second placing behind No.1 Dustin Johnson at the recent WGC-Mexico Championship, and is adamant his 15th PGA Tour victory is close. The top three finishers in the top 10 and ties who are not already qualified will earn exemptions into the Open Championship in July.
Off camera, you can hear Hatton's caddie say, "No".
"I'm really happy to be playing here for the first time".
"I've been messing around with a 64-degree lob wedge as I think that could be beneficial around (Augusta)", McIlroy, a victor of the USA and British Opens and the PGA Championship, said.
Day later revealed he had been struggling with a sore back last week and underwent an MRI scan on Monday which indicated a tear in a disc.