Saving fuel throughout a 66-lap green-flag run to the finish, Justin Allgaier collected his first NASCAR Xfinity Series victory of the season—and the first this year for JR Motorsports—in Monday’s twice-rain-delayed Alsco Uniforms 300 at Charlotte Motor Speedway.

Allgaier, the pole winner, beat runner-up John Hunter Nemechek to the finish line by 7.829 seconds, as the top three finishers—including third-place Cole Custer—stretched their fuel mileage from a Lap 135 restart to the end of the race.

Austin Hill and Ty Gibbs, both of whom pitted for fuel in the closing stages, claimed the fourth and fifth positions, respectively.

“I’m speechless, man,” said Allgaier, who led a race-high 83 laps. “I didn’t know how much to save. Just lucky we had enough… I just cannot say enough about (crew chief) Jim Pohlman, everybody on the No. 7 team.

“It’s not been for lack of speed this year. We’ve battled. Tonight, was kind of the opposite. We had to go slow to go fast.”

Nemechek led 57 laps, but Allgaier build a substantial lead at the end while conserving enough fuel to finish the race—and to do a celebratory burnout.

“We were racing each other pretty hard, and I burned my stuff up trying to get to him—and get around him,” Nemechek said. “I should have been a little more patient, I guess. But overall, really solid day. Good points day for us. I think that extends our points lead.”

In fact, Nemechek collected his fifth top-two finish of the season (with wins at Fontana and Martinsville) and holds a 10-point lead over Hill in the series standings.

But Allgaier and Nemechek might not have been left to battle for the win, had a radio issue not adversely affected Gibbs’ winning chances.

The driver of the No. 19 Toyota, who won last year’s Xfinity championship before graduating to the NASCAR Cup Series, led 52 laps and swept the first two stages of the race. But an extended pit stop, during which Gibbs’ crew changed his steering wheel (which housed a faulty radio button) dropped him to the rear of the field for a restart on Lap 98. That ended Gibbs’ challenge for the win.

Parker Retzlaff ran sixth, followed by Jeb Burton, Carson Hocevar, Jeb Burton and Sammy Smith.

The race was delayed from Saturday by rain and restarted on Monday morning. But rain intervened again after the completion of the first stage, delaying the finish until after the running of the Coca-Cola 600 NASCAR Cup Series race, won by Ryan Blaney.