The American will also share a separate $3 million team prize with his Crushers GC teammates, after finishing four shots clear of Peter Uihlein (68).
Howell (63) was just one stroke behind co-leaders Uihlein and Talor Gooch heading into Sunday and gave his competitors little chance as he produced six of eight birdies on the front nine.
"It's big we got the team win," Howell said in a televised interview after the round. "I played here many times before and had an idea of what to expect coming in. But around this place, man, there's double bogeys everywhere, so you never know."
The day could scarcely have gone worse for Gooch, who carded a five-over par 76 to finish tied for 11th. And there was only bitter disappointment for Uihlein, for whom the win slipped out of reach when he landed in the trees en route to a triple bogey on the par-four 12.
Asked what he might have done differently, Uihlein joked: "Skipped the 12th."
"It's just a hole that does not set up well for me. I don't like the look of it. But, you know, I'm proud of the way I battled," he said. "Other than that hole, it was a pretty good day."
South African Branden Grace carded a four-under par 67 to finish third.
The Saudi-backed circuit, whose slogan promises "golf, but louder," produced its usual party atmosphere but little in the way of competitive drama as many of the marquee-calibre names it lured away from the PGA Tour failed to make an impact in the 2023 season kickoff.
LIV's 2023 season kicked off amid ongoing bitterness with the PGA Tour, as Chilean Mito Pereira, who finished third in last year's PGA Championship, and Colombian Sebastian Munoz joined LIV earlier this month.
