Bell, who had won in his last three starts at the 1.058-mile oval, restarted third at the start of a two-lap overtime behind Cole Custer and Sheldon Creed.
Custer moved quickly to the lead, but Creed and Bell closed in and after Creed got into Custer, which opened the door for Bell to move into the lead on the final lap. Bell then held off Creed by 0.254 seconds at the checkered flag for his fourth consecutive win at New Hampshire.
Bell is the fourth different driver to win in Joe Gibbs Racing’s No. 20 Toyota and picked up his 18th career victory.
“I feel so bad for Sheldon. He’s been really, really close to winning one of these things. Today, he did everything right to win that race,” Bell said. “He restarted in the right lane, good push and coming to the white flag he got Cole loose, which opened the door for me.
“This car was really, really good early in the race but once I lost track position, I was just another guy. We got really lucky there.”
Custer, who led the most laps (114 of 203), ended up third and maintains his lead in the series standings. Justin Allgaier was fourth and Carson Kvapil was fifth.
Completing the top 10 were Ryan Sieg, Parker Kligerman, Riley Herbst, Alex Bowman and Corey Heim.
Stage 1
Sam Mayer grabbed the lead on a restart six laps remaining and held off Sammy Smith by 1.133 seconds to earn the Stage 1 win. Herbst was third, A.J. Allmendinger fourth and Allgaier fifth.
With damp conditions still present, NASCAR had teams start the race on wet weather tires for the first time in series history on an oval track. They ran 11 laps before NASCAR put out a competition caution to allow teams to change to slick tires.
Stage 2
Bell led every lap and cruised to a 4.172-second win over Justin Bonsignore to take the Stage 2 win. Custer was third, Creed fourth and Chandler Smith ended up fifth.
Stage 3
During the break between Stages 2 and 3, all the lead lap cars elected to pit with Custer first off pit road. Allgaier had an extended stop as several lug nuts fell off a left-side tire. Custer led Bell and Chandler Smith when the race resumed with 102 laps remaining.
With 70 laps remaining, Custer had built an almost 3-second lead over Bell, but all drivers still needed to pit once more for fuel.
Ryan Sieg was among the first drivers to hit pit road with about 55 laps to go to make their final green flag stop for new tires and fuel to make it to the finish. Bell was next with 51 laps remaining.
Once the cycle of stops was completed with 36 laps to go, Custer emerged with a more than 4-second lead over Bell with Chandler Smith in third.
Armani Williams spun out in Turn 2 and down the backstretch on lap 168 to bring out a caution which sent most of the lead lap cars down pit road again for fresh tires.
Once again, Custer was first off pit road. Jesse Love and Kvapil remained on the track and led Custer when the race returned to green with 26 laps remaining. Kvapil jumped to the lead and Custer to second on the restart.
While trying to go three-wide, Chandler Smith got spun around after contact with Creed to set up another restart with 19 laps to go and Kvapil ah”ead of Custer.
Mayer went four-wide on the restart which triggered a 10-car accident that also collected Bonsignore and Austin Hill, among others. Custer led Kvapil and Bell with 12 laps remaining.
A wreck involving Nathan Byrd and Hailie Deegan set up another restart with six laps to go and Custer still out front.
Deegan and Mason Massey wrecked with three to go to bring out a caution and send the race into overtime with Custer ahead of Bell and Creed.
