By PETE IACOBELLI AP Sports Writer

 DARLINGTON, S.C.  — Justin Allgaier used a dominating performance on Saturday to win his first Xfinity race of the season and the third of his career at Darlington Raceway.

Allgaier led 119 of 147 laps, sweeping both stages as he finished ahead of Austin Hill and defending series champion Cole Custer.

Allgaier moved past Hill early in the second stage and never gave up the lead, staying in front for the final 95 laps.

“I think having a little gray hair today really helped me out, though, with those long green-flag runs,” the 37-year-old Allgaier said. “Being able to know what’s worked in the past here.”

The run ended a frustrating season so far for Allgaier, who had been in contention many times this year only to come up short of the checkered flag. He had a flat tire while leading with five laps left at Phoenix in March. Last month at Dover, Allgaier’s fast car ended 17th as the team’s strategy in the rain backfired.

“To have the speed that we’ve had week in and week out and to just not be able to put it all together. It seems we’ve failed miserably on the execution side,” Allgaier said. “Today was anything but that.”

Allgaier said his team’s pit stops were stellar and he was able get back to the track in prime position to stay out front.

“What I saw today was execution by every person that’s a part of the (No. 7) team,” he said.

Only two of the five cautions in the race were for accidents — and they proved to be Allgaier’s trickiest moments.

The first came with 39 laps to go after Hailie Deegan wrecked and the other came with 16 laps left when Kyle Sieg spun out. Allgaier sped off from the field both times and cruised to his 24th career Xfinity victory to equal the total of JR Motorsports owner Dale Earnhardt Jr.

Allgaier’s win also gave him a series-best 267 top 10s, breaking a tie with all-time series wins leader Kyle Busch.

Allgaier also moved up in Darlington history, his three wins here tying for fifth with the late Dale Earnhardt, Matt Kenseth and Geoff Bodine.

Sam Mayer, Allgaier’s JR Motorsports teammate, finished fourth and AJ Allmendinger fifth.

Hill, who was runner-up to Denny Hamlin in last September’s Xfinity race at Darlington, blamed himself for another second-place showing.

“I just couldn’t get into Turn 1 on restarts like I really needed to all day and I think a lot of it’s just me,” Hill said. “I’ve just got to figure out what to do differently.”

Three-time Cup Series winner William Byron was the biggest name in the field and figured to contend at a track where several from the sports’ top series have won before. But Byron’s chance ended when he hit the wall early in the race.

A bad pit stop left him three laps down less than 15 laps in, and he ended up finishing 11th.

The series takes next week off before resuming at Charlotte Motor Speedway on May 26.