Allmendinger this year agreed to his first full-time season since 2018 in a deal with Kaulig Racing. He's friends with team owner Matt Kaulig and has slowly been lured back into NASCAR as a favor to the team.
He was Kaulig's "Trophy Hunter" last year in 11 races he was entered solely to win for the team. Kaulig then convinced Allmendinger to run for the Xfinity Series championship while also helping the organization move to Cup next season.
The victory was the sixth in the Xfinity Series for Allmendinger, who retired at the end of the 2018 season rather than drive for an uncompetitive team.
Allmendinger was in tears when he climbed from his winning Chevrolet.
"It's emotional. Hell, you don't know when you are going to do this again," Allmendinger said. "You never know if this is the last one. Matt Kaulig, I love you, man."
Kaulig Racing has eight Xfinity Series victories since its 2016 formation. Four of the wins were by Allmendinger.
Allmendinger said he holds Kaulig in such high regard that he's often ill before races from the pressure to deliver for the team.
"I want to win so bad for Matt every week. It's hard to put into words what he means to me and truly how bad I want to win for him," Allmendinger said. "It's the same thing as wanting to win for Roger Penske. It means that much to me that he believes in me. Thank you for this opportunity because I don't take it for granted."
Allmendinger led 44 laps, including the final 13 after passing Hemric on the restart.
Hemric finished second and led a race-high 74 laps in a Toyota for Joe Gibbs Racing. Brandon Jones, his JGR teammate, was third.
IndyCar driver Santino Ferrucci, in his second NASCAR race, finished 13th.
Ty Dillon has had a terrible run through three races with Joe Gibbs Racing. A broken radiator ended his race last week at Homestead and he crashed with 20 laps remaining Saturday when the battery in his spotter's radio died.
Drew Herring was switching over to a new battery and not able to inform Dillon he was not clear to move up a lane when Dillon improperly cut in front of Brett Moffitt. Dillon was additionally penalized two laps when too many crew members went over the wall to fix the damage and Dillon finished 30th.