FORT WORTH, Texas – Harrison Burton played spoiler to Noah Gragson’s NASCAR Xfinity Series title hopes with a thrilling last-corner victory in Saturday’s O’Reilly Auto Parts 300 at Texas Motor Speedway.

Burton, who rallied back from a lap-108 spin through the grass on the frontstretch, chased down Gragson inside the final two laps and powered inside Gragson’s No. 9 Chevrolet coming off turn four to the checkered flag.

Midway through the race, it looked like things might be over for the driver of the No. 20 DEX Imaging Toyota Supra, but Burton kept his head down, kept charging and ultimately collected his third career Xfinity Series win.

“We had such a fast race car. I’ve never driven anything harder than that last corner in my life. I don’t know how it stuck,” admitted Burton in victory lane. “I think this might be my first win with Morton Buildings on the hood and with DEX (Imaging) as well. This Toyota Supra was so fast. I’ve never spun out and then come back and won, so that’s kind of cool. We were obviously pushing the limits all day with speed. That’s just kind of what we came to do was to be fast and to win our first stage of the year was a good sign.

“To do what we did on that last lap was incredible. I don’t know how it happened, but I’m pretty damn glad it did.”

The complexion of the race – and the playoffs – changed after a crash on a restart with 25 to go.

Justin Allgaier and Ross Chastain were on the front row at the time, and Allgaier charged turns one and two in an attempt to grab the top spot, but washed up into Chastain on corner exit.

That led to more contact between the two going down the backstretch, which ended in a four-car crash that eliminated playoff contenders Allgaier and Brandon Jones, as well as Jeremy Clements, who slammed into Allgaier’s car going into the third turn.

Chastain was able to continue with a wounded Chevrolet, but ended up 16th, on the tail of the lead lap.

Meanwhile, Austin Cindric emerged with the race lead after the contact between Allgaier and Chastain, bringing the field back to green for a 15-lap shootout to the finish.

However it was Gragson that fired off better, seizing control when Cindric got loose and washed up the race track in turns three and four on lap 186 and appearing to have certain victory in his sights.

Anthony Alfredo was running second and Burton third at that point, with Alfredo holding off Burton in a torrid battle lap after lap before Burton finally snuck by coming to the two to go signal.

Harrison Burton (20) takes the checkered flag ahead of Noah Gragson to win Saturday at Texas Motor Speedway. (Toyota Racing photo)

At that point, it appeared Gragson would be able to hang on with an eight tenth of a second cushion, but Burton erased that deficit as Gragson’s car got tighter and tighter before finally making the winning move.

“That (continuing to charge) was the only thing that was in my head. My team had talked to me about what the other guys were doing through three and four to get speed,” Burton explained. “I kind of timed that by about three or four and it stuck. I don’t know. Hats off to the 9 (Noah Gragson) for racing me clean today and hats off to the rest of the competitors. That was such a fun race.

“What a cool place to win at – we get to go home with cowboy hats; that’s awesome,” added Burton, who joined his father Jeff as a winner at Texas.

Jeff Burton won the inaugural NASCAR Cup Series race at the track in 1997.

Gragson’s second-place finish was heartbreak for him in more than one way. Had he took the checkered flag in first, he would have locked into the Championship 4.

Instead, Gragson is 24 points back of the cut line and in a virtual must-win situation with only next weekend’s race at Martinsville (Va.) Speedway remaining in the penultimate round of the playoffs.

Alfredo crossed the line third, marking his best finish of the season in his final scheduled start with Richard Childress Racing for the year, with Cindric and Brandon Brown filling out the top five.

Sixth through 10th were Michael Annett, Justin Haley, Ryan Vargas, Josh Williams and Tommy Joe Martins.

Ahead of the cutoff race for the round of eight, Chase Briscoe is the only driver locked in to the championship round at Arizona’s Phoenix Raceway, by virtue of his Oct. 17 win at Kansas Speedway.

Cindric (+14), Allgaier (+8) and Haley (+4) are inside the top four on points, with Jones, Chastain, Gragson and Ryan Sieg on the outside looking in going into Martinsville.

Briscoe’s day went south with a mechanical failure 35 laps into the race. He spent time behind the wall and ended up finishing 24th, 16 laps off the pace.

The NASCAR Xfinity Series season continues Oct. 31 at Martinsville Speedway, with the tour’s second race at the .526-mile paper clip in a quarter century.

To view complete race results, advance to the next page.