FORT WORTH, Texas — Sam Mayer made a last-lap pass and held on to win by a matter of inches ahead of Ryan Sieg at Texas Motor Speedway in one of the closest finishes in NASCAR Xfinity Series history on Saturday.

Mayer was high against the outside wall after the two cars banged side-by-side on the way to the checkered flag. The final margin was .002, matching the second-closest finish in series history.

“That’s unreal. I mean I was like a second and a half back probably at one point. So to make up that much time in that little amount of time is certainly unreal,” Mayer said. “We led the most important lap. … We didn’t dominate by any means, but we certainly worked our tails off to get to that point to win like that.”

Justin Allgaier finished third after leading 117 of the race’s 200 laps.

Sieg went from 10th place to first in a span of four laps just before the race’s final caution. After the restart with 11 to go, Sieg stayed in front until the final lap when Mayer was able to get the No. 1 JR Motorsports Chevrolet under and by him on the backstretch.

Off the final turn, Sieg got back to the inside of Mayer but came up just short in the No. 39 Ford of getting his first win in 342 career starts for the RSS Racing team owned by his family.

“The first emotion is definitely disappointment. We had it. We were leading at the end,” Sieg said. “We got up front but we just got too tight. I was doing all I could do. I was changing lines, changing brakes, changing everything. It was just that close. I saw him coming. I was doing all I could do. In the end I was just trying to run him into the wall to win the race. We were just so close.”

It was the fifth career win for Mayer, and his first this season. He led four different times for a total of only five laps.

AJ Allmendinger was fourth, followed by Cole Custer, Austin Hill, Ryan Truex, Sammy Smith, Jesse Love and Anthony Alfredo.

While Allgaier dominated the race without getting the win, he still finished in the top 10 for the 266th time in his career. That matched Kyle Busch’s record for the most in Xfinity Series history.

Allgaier made his 446th career start, and has won 23 times.

The Associated Press contributed to this story.