Allgaier’s No. 7 JR Motorsports Chevrolet team was one of five that began the race having to serve a pass-through penalty on pit road because of multiple pre-qualifying inspection failures.
The penalty left Allgaier a lap down early, but he eventually made his way back up front and took the lead for the first time on lap 85 of 110.
He lost the lead to Trevor Bayne but reclaimed it when multiple cars in front of him wrecked on a late-race restart.
Allgaier then survived two overtime restarts, including a side-by-side duel with Sheldon Creed on the final lap. He clipped Creed by 0.005 seconds for his second win of the 2023 season and first-ever on a superspeedway.
“I’ve wanted to win here so bad, and we’ve been so close,” Allgaier said. “This team, I can’t say enough. To come through the adversity we had to come through and not really be sure we were going to have it at the end.
“We just did all the things we need to do.”
Daniel Hemric ended up third, Parker Kligerman fourth and Cole Custer rounded out the top five.
Completing the top-10 were Parker Retclaff, Ryan Sieg, Anthony Alfredo, Gray Gaulding and Justin Haley.
Stage 1
Austin Hill held off his teammate Creed by 0.143 seconds to take the Stage 1 win. Chandler Smith was third, Brett Moffitt fourth and Alfredo was fifth.
Riley Herbst, who had been complaining of problems with his No. 98 Ford early in the race, fell off the pace on the final lap and was forced to pit road with a blown left-front tire.
Stage 2
Creed grabbed the lead with three laps to go and held off Hill by 0.407 seconds to claim the Stage 2 win, his fourth stage victory of the 2023 season. Custer was third, Sammy Smith fourth and Hemric fifth.
Alfredo got loose and got into Brandon Jones on the frontstretch early in the stage which triggered a multi-car wreck that collected multiple cars, including Joe Graf Jr., Ryan Sieg, Natalie Decker, Connor Mosack and Allgaier.
Stage 3
During the break between Stages 2 and 3, all the lead-lap cars pit with Sam Mayer first off pit road with a fuel-only stop. He led the way on the restart with 34 laps remaining in the race.
With 25 laps to go, Bayne maintained a small advantage over Kligerman with Sammy Smith close behind in third.
On lap 82, Mayer – who has won two of the last four series races – used the inside line to power past Bayne and into the lead.
Allgaier grabbed the lead for the first time in the race with 15 laps to go. Bayne got back around him for the top spot on lap 87.
Jeb Burton spun off Turn 4 which triggered an incident that collected three other cars to place the race under caution and set up a restart with two laps to go.
An aggressive block attempt by Bayne on Hill shortly after the restart set off a chain reaction wreck that collected many of the top contenders.
Allgaier inherited the lead after the crash and led the way heading into a two-lap overtime.
A multi-car wreck erupted in Turn 3 after the restart which sent the race into a second two-lap overtime and Allgaier still out front.