Reigning series champion Zane Smith looked like he was going to turn a fuel-mileage gamble into a win but was wrecked by Ty Majeski while racing for the lead with six of the originally scheduled 160 laps to go.
Enfinger, who ran third at the time, inherited the lead but the race went into a two-lap overtime. Enfinger cleared quickly to the lead on the restart and held off Christian Eckes by 0.256 seconds to claim his second win of the 2023 season.
With the victory – the ninth of his career – Enfinger also collected a $50,000 bonus as part of the Triple Truck Challenge.
“Thank you everybody for believing in us. It’s been a rocky year,” Enfinger said. “These last five races I feel like we’ve come into our own. We’ve had speed.
“I was pretty disappointed yesterday. I feel like I failed my (qualifying) lap and we were 10th. I didn’t feel like we were a contending truck but (crew chief) Jeff Hensley made great calls and overall, just a great day.”
Enfinger, 38, also took the occasion to announce he and his wife, Michelle, were expecting their second child.
Stewart Friesen ended up third, Carson Hocevar fourth and Chase Purdy rounded out the top five.
Completing the top-10 were Matt DiBenedetto, Ben Rhodes, Nick Sanchez, Jesse Love – who was substituting for Corey Heim – and Jake Garcia.
Heim, who was the series points leader entering the race, missed it due to an illness.
Stage 1
Enfinger, who elected not to pit on the late-stage caution, held off Majeski in a one-lap dash to earn the Stage 1 win, his first of the 2023 season.
Rhodes ended up third, Smith fourth and DiBenedetto – who had also stayed out – was fifth.
Stage 2
Friesen claimed the Stage 2 win under caution when Conner Jones wrecked with three laps remaining and there wasn’t enough time to restart the race.
Majeski ended up second, Sanchez third, Hocevar fourth and Eckes fifth.
Chris Hacker got into Jack Wood and spun him off Turn 4 on lap 56 to bring out a caution, which sent several lead-lap trucks down pit road. Majeski stayed out and inherited the lead on the restart with nine laps to go.
Stage 3
Following the break between Stages 2 and 3, several lead-lap trucks pit for new tires but Enfinger stayed out and returned to the lead when the race went green on Lap 77.
Hailie Deegan wrecked in Turn 3 after getting hit by Sanchez, which brought out the seventh caution of the race on lap 88.
A handful of Trucks, including Smith, decided to pit but Enfinger remained on the track and in the lead when the race resumed on lap 94.
With just under 40 laps remaining, a round of green-flag pit stops began for those drivers who had not pit since the stage break.
Hacker, however, spun again after contact with Josh Reaume on Lap 126, which allowed most drivers to pit for new tires and fuel under the caution. Smith elected to remain on track and inherited the lead on the restart with 29 laps to go.
Majeski, trying to grab the lead on a restart with six laps remaining, got loose and into Smith which wrecked both trucks and sent the race into overtime with Enfinger in the lead.