Nemechek had a dominant car throughout the race – leading 137 of 206 laps – but had to fend off repeated challengers on three restarts in the final 40 laps, including the final one in overtime.
A multi-car wreck on lap 197 sent the race into a two-lap overtime with Nemechek in the lead and Custer lined up alongside him on the restart.
Nemechek was able to quickly clear for the lead and just after he took the white flag to start the final lap, Custer got into Sheldon Creed and both wrecked on the frontstretch, which allowed Nemechek to claim the win under caution.
The win is Nemechek’s fourth this season and second consecutive following a victory last weekend at Atlanta. He currently has three consecutive finishes of second or higher.
“I’m just so proud of everyone at this No. 20 team at Joe Gibbs Racing. I’m just so thankful for the opportunity,” Nemechek said. “I wish Coy (Gibbs) was here to celebrate with us. He was a huge advocate for this to happen this year.
“Things were clean on the race track today. I think we had our first clean race all year. That’s really good. Huge shoutout to all the fans for being here. It’s an amazing crowd.”
Chandler Smith ended up second, Austin Hill third, Daniel Hemric fourth and Sammy Smith – who started the race from the rear of the field – ended up fifth.
Completing the top-10 were Justin Allgaier, Jeb Burton, Josh Williams, Brett Moffitt and Mason Massey. Creed ended up 21st and Custer 22nd, both one lap down.
Stage 1
Allgaier claimed the Stage 1 win under caution as he was the leader following a wreck involving Chris Hacker with three of 45 laps remaining. Nemechek was second and Custer third.
Allgaier and Nemechek battled side-by-side for several laps – including some contact – before Allgaier finally cleared him for the lead on lap 27.
Stage 2
Sammy Smith passed Parker Retzlaff with one to go and held him off to take the Stage 2 win. Creed was third, Brandon Jones fourth and Williams fifth.
Allgaier, who was battling back from the rear after a pit road penalty, and eight other drivers were involved in a pileup on the frontstretch on a restart on lap 71. Parker Kligerman and Ryan Sieg were knocked out of the race.
Stage 3
Following the break between Stages 2 and 3, a handful of lead-lap cars pit but Sammy Smith remained on the track and in the lead to begin the final stage.
Nemechek got around Sammy Smith on a restart on lap 107 to return to the lead as Smith dropped to second and Creed moved to third.
With 70 laps to go, Nemechek had built a more than 2-second lead over Sammy Smith as Creed and Jones battled for third.
Creed and Sammy Smith were among those who kicked off a final round of green flag pit stops with 52 laps remaining to take on new tires and fuel to make it to the end of the race.
Kyle Sieg spun around off Turn 4 after getting hit by Josh Berry to bring out a caution just before the completion of the green-flag pit cycle.
After the remaining cars made their pit stops under caution, Nemechek inherited the lead and led the way on the restart with 33 laps to go.
A late-race wreck by Retzclaff in Turn 1 put the race under caution and set up a late restart with four laps to go while Nemechek remained out front.
A multi-car wreck on the restart sent the race into a two-lap overtime with Nemechek in the lead followed by Chandler Smith, Custer, Creed and Hill.