Ty Gibbs led on a restart with five of 82 laps remaining, but William Byron got alongside him coming out of Turn 1 with Larson in third.
As Gibbs and Byron raced side-by-side through the inner loop, they both spun off course, which allowed Larson to pass them and inherit the lead. He then spent the final four laps deftly holding off talented road racer A.J. Allmendinger, clearing him by 0.273 seconds for the win.
The victory is the first in the series for Larson since the 2018 season and he was making just his second start of the year. Larson, the reigning Cup Series champion, now has 13 career Xfinity wins.
“I got lucky,” Larson said. “My only shot really was if (Gibbs) and (Byron) got racing. I just wanted to help Willy down the frontstretch as much as I could and they got battling in the esses.
I tried to help him to get clear in the bus stop and they raced side-by-side into there, got together, the seas parted and I was able to get through.
“Then I had A.J. behind me and I just tried to hit my marks as beast I could. He definitely had me nervous out front of him. It’s cool to get a win here.”
Sammy Smith finished third, Noah Gragson was fourth and Kaz Grala rounded out the top-five.
Completing the top-10 were Sam Mayer, Riley Herbst, Sheldon Creed, Josh Berry and Jeremy Clements.
Byron ended up 25th while Gibbs finished 27th.
Stage 3
Following the break between Stages 2 and 3, several lead-lap cars pit but Byron stayed on the track and remained in the lead.
On the restart on Lap 45, Byron was followed by Gibbs and Allmendinger.
Creed was the first of the lead-lap cars to make its final pit stop on Lap 52 to take on new tires and fuel to make it to the finish of the race. Byron and Gibbs followed on Lap 53.
On Lap 59, Daniel Hemric locked up his brakes plowed nose-first into the tire barrier in the carousel to bring out the seventh caution of the race.
Those cars that had yet to pit elected to do so. Gibbs was among those who remained on the track and moved back into the lead.
The caution was extended by several laps after Myatt Snider brought his car from the garage after repairs but it began dropping fluid on the track.
On the restart on Lap 68, Gibbs was followed by Byron, Gragson, Larson and Allmendinger.
Larson quickly bolted to second on the restart only to see Byron reclaim it.
With 10 laps remaining, Gibbs maintained a lead over Byron of just under a second. Larson ran third and Allmendinger fourth.
On Lap 76, Ross Chastain got stuck in the sand trap which forced NASCAR to throw another caution.
Gibbs remained the lead on the restart with five laps remaining. He was followed by Byron, Larson, Smith and Allmendinger.
As Gibbs and Byron raced side-by-side through the inner loop, both cars spun off course and Larson inherited the lead.
With two laps to go, Larson led but Allmendinger was right on his rear bumper with Smith in third.
Stage 2
Byron cruised to the Stage 2 win over Gibbs by 1.4 seconds.
Allmendinger finished third, Gragson fourth and Larson rounded out the top-five.
Following the break between Stages 1 and 2, a handful of cars pit but Smith remained on the track and remained in the lead.
On the restart on Lap 24, Smith was followed by Byron, Creed and Larson.
Larson went to the outside of Smith on the restart to take the lead for the first time in the race.
On Lap 25, Byron out-braked Larson entering Turn 1 to reclaim the lead.
NASCAR was forced to display a caution on Lap 29 after Alex Labbe suffered a flat tire and came to a stop in the inner loop.
When the race resumed on Lap 30, Byron led the way followed by Larson and Gibbs.
On Lap 31, Kris Wright’s car came to a stop off Turn 1 which forced NASCAR to throw another caution.
The race returned to green on Lap 34 with Byron still out front, followed by Larson and Gibbs.
With five laps remaining in the stage, Byron held a 1.24-second lead over Creed as Larson ran third.
Stage 1
Smith passed Allmendinger on a restart with two laps remaining and held on for the Stage 1 win.
Grala was third, Clements fourth and Kyle Weatherman rounded out the top-five.
Byron started on the pole and took control early.
The race was placed under caution on Lap 5 after Justin Allgaier spun in the esses and slammed into the barrier, which brought an early end to his day.
Just a handful of cars pit. On the restart on Lap 9, Byron led the way followed by Gibbs, Allmendinger and Cole Custer.
Gibbs grabbed the lead on the restart only to see Byron recapture it in the inner loop. Gibbs moved back ahead of Byron on Lap 11.
Patrick Gallagher stalled in the inner loop on Lap 16 which brought out the second caution of the race.
Most of the lead-lap cars elected to pit with Gibbs first off pit road. Allmendinger stayed on the track and inherited the lead. The race resumed with two laps remaining in the stage.