The #14 Vasser Sullivan-run RC F of Hawksworth and Ben Barnicoat had led for over 100 laps of the six-hour race when it received a drive-through penalty for pitlane speeding after its final pitstop.
Hawksworth, who had just taken over from his team-mate, rejoined in second place and chased down the leading Corvette of Antonio Garcia, passing it in the final hour with an aggressive lunge, but he then had to fend off the Risi-run Ferrari of Daniel Serra to the finish top of the GTD Pro class.
“We’re not sure what happened and need to investigate what went wrong,” said Hawksworth of the penalty. “There was no pitlane control as soon as I left the box, and I went over the speed limit.
“I got the speeding penalty and then came out in second. At that point, I just couldn’t believe it might slip through our hands, but I managed to get a move around the Corvette to win.
“This is an unbelievable day. To win both GT categories is unreal. I’ve been with this programme a long time, and this is by far the greatest day in the programme’s history.”
Barnicoat added: “In a situation like that, when you’re in P2 in the final moments of the race there’s no better driver in the car than Jack and he made an amazing move and got us the win.
“What a great day for the championship. This puts us with a nice lead to head into the second half of the season.”
The #14 Lexus was headed across the finish line by its sister car, driven by the pro-am trio of Aaron Telitz, Frankie Montecalvo and Parker Thompson – who outpaced the entire GTD Pro field as well as their own category rivals.
“It was a team effort today,” said Montecalvo. “We made zero mistakes and finally it went our way. There’s really no other way to put it.
“We’ve been up front all year. We’ve had race wins taken away from us so many times before in the #12 car especially, and it’s amazing that we can finally bring it home P1.
“Everyone on this Vasser Sullivan team – there were zero mistakes.”