Allmendinger, who led 28 of the 46 laps including the first 14, almost saw his path to a win derailed when he got spun on a restart after contact with Aric Almirola on Lap 20.
That sent Allmendinger back to 26th place and the fight was on from there. Allmendinger managed to work his way back to the lead after getting into then-leader Sheldon Creed on Lap 33 and sending him off the course.
Despite repeated attempts by William Byron to try catch him in the final 14 laps, Allmendinger fought off each challenge and held on to win by 0.853 seconds.
The win is the first of the season for Allmendinger in the Xfinity Series and 16th of his career (11 have come on road courses including this race last season).
“William Byron is one of the best ones in the sport right now, seeing all Cup races he’s winning. I knew it was going to be tough,” Allmendinger said. “I was just trying to fight to get back up to the front there.
“I hate I had contact with Sheldon. I was trying to stay off him but I hate that happened. This car was really hooked up. With all the damage we had, it definitely hurt the car. Man, I’m probably too old for this job.”
Allmendinger said winning never gets old.
“I spent a lot of years not winning anything so I’m going to celebrate every one like it’s my last one because you never know. As much pressure as I put on myself I’m always going to try to live up to it.”
Ty Gibbs finished third, Sammy Smith fourth and Justin Allgaier rounded out the top-five.
Completing the top-10 were Daniel Hemric, Sam Mayer, Josh Berry, Creed and Riley Herbst.
Sammy Smith, Allgaier, Hemric and Mayer were the four highest finishing series regulars in the race and qualified for the $100,000 Dash4Cash bonus in next weekend’s race at Richmond, Va.
Stage 3
As the final stage got under way, the race was under caution for an incident involving Cole Custer.
Several lead-lap cars pit but Creed remained on the track and in the lead on the restart on Lap 33. Creed was followed by John Hunter Nemechek and Almirola.
Allmendinger powered into second place on the restart as Almirola ran third.
On Lap 33, Allmendinger got into the back of Creed and knocked him from the lead as he and Byron ended up racing side-by-side for the top spot.
Allmendinger finally was able to put some distance between himself and Byron as Nemechek moved into third.
With 10 laps remaining, Allmendinger held a small advantage over Byron as Sammy Smith moved into third.
With five laps to go, Allmendinger’s lead over Byron expanded to 1.1 seconds as Gibbs moved into third, 10.3 seconds behind the leader.
Stage 2
At the completion of Lap 30, Creed was in the lead and earned the Stage 2 win as the race was placed under caution after Cole Custer got stuck in the gravel trap.
Ryan Sieg was second, Nemechek third, Almirola fourth and Berry rounded out the top-five.
As the second stage got under way, Allmendinger led the way over Creed.
On Lap 16, Allmendinger and several others elected to pit which turned the lead over to Creed.
Austin Hill was forced to take his No. 21 Chevrolet to the garage as he was unable to shift between second and third gear.
NASCAR displayed a caution on Lap 18 after Preston Pardus’ No. 50 car stalled on the track near Turn 1.
A handful of cars pit under the caution but Creed remained on the track and in the lead when the race returned to green on Lap 20.
Allmendinger and Aric Almirola got together in Turn 1 after the restart but both were able to remain in the race. Allmendinger, however, dropped to 26th in the running order.
Brandon Jones had a tire go down and tried to make it back to pit road but dropped debris on the track which forced NASCAR to place the race under caution on Lap 22.
On the restart on Lap 23, Creed led the way followed by Byron, Allgaier, Sammy Smith and Custer.
Byron briefly got around Creed on Lap 24 but Creed came right back and reclaimed the lead as Sammy Smith moved to third.
Byron again got past Creed in the esses on Lap 27 and this time he was able to pull away.
Brett Moffitt came to a stop on the track on Lap 28 which brought out the fourth caution of the race.
Most of the lead-lap cars pit with Creed first off pit road. Parker Kligerman stayed out and inherited the lead. Jeremy Clements had to restart from the rear of the field for pitting outside his pit box during his stop.
Stage 1
At the completion of Lap 14, Allmendinger was in the lead and earned the Stage 1 win.
Creed was second, Kligerman third, Gibbs fourth and Byron rounded out the top-five.
Allmendinger started on the pole, lost the lead early to Creed, then regained it to lead Lap 1.
NASCAR was forced to display a caution on Lap 9 when Carson Hocevar’s No. 09 came to a stop on the track.
Most of the lead-lap cars elected to pit with Hill the first off pit road. Allmendinger remained on the track and in the lead. Sieg had to restart from the rear of the field after speeding on pit road.
The race resumed on Lap 10 with Allmendinger out front.
With five laps to go in the stage, Allmendinger maintained a 1.7-second lead over Kligerman as Herbst ran third.
Creed, on four new tires, moved into second behind Allmendinger with three laps remaining.