Justin Allgaier, driver of the #7 BRANDT/Celebrating the Future of AG Chevrolet, celebrates in Victory Lane after winning the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Brian Lawdermilk/Getty Images)

By Reid Spencer, NASCAR Wire Service

JOLIET, Ill. – Justin Allgaier had the drive of his life. Brendan Gaughan was hanging on for dear life.

Justin Allgaier, driver of the #7 BRANDT/Celebrating the Future of AG Chevrolet, takes the checkered flag to win the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Jeff Zelevansky/Getty Images)

But both drivers were winners at Chicagoland Speedway.

Grabbing the lead with a bold move to the inside after a restart on Lap 186 of 200, Allgaier, an Illinois native, captured the big prize at his home track — a victory in Saturday’s TheHouse.com 300 NASCAR XFINITY Series regular-season finale.

Gaughan rallied from an equalized tire that put him three laps down to finish 13th on the lead lap and nail down the final spot in the NASCAR XFINITY Series Playoffs.

With a push from regular-season champion and JR Motorsports teammate Elliott Sadler, Allgaier powered his No. 7 Chevrolet to the bottom entering Turn 1 on Lap 186, passing both pole-sitter Erik Jones and Ryan Blaney.

Justin Allgaier, driver of the #7 BRANDT/Celebrating the Future of AG Chevrolet, celebrates in victory lane after winnicelebrates in victory lane after winningduring the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Sean Gardner/Getty Images)

But Allgaier was far from home free. A caution for Ryan Reed’s spin in Turn 2 — under hard racing against Darrell “Bubba” Wallace Jr. — slowed the field for the fifth and final time and set up a restart with seven laps left.

Once again, Allgaier surged into the lead, with Jones chasing. But Jones had changed lanes and moved to the outside of Sadler before he reached the start-finish line and was slapped with a pass-through penalty that ended his winning chances.

Allgaier took the checkered flag 1.772 seconds ahead of charging Kyle Larson, who fought back from a late pit-road speeding penalty to finish second. Sadler came home third, followed by Daniel Hemric and Austin Dillon.

“Justin had a great restart there,” said team owner Dale Earnhardt Jr., who has four cars in the Playoffs. “He found an opportunity and seized it.”

Justin Allgaier, driver of the #7 BRANDT/Celebrating the Future of AG Chevrolet, celebrates with a burnout after winning the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Jeff Zelevansky/Getty Images)

“This is incredible, man,” said Allgaier, who won for the second time this year, the second time at Chicagoland Speedway and the fifth time in his career. “I’ve been fortunate enough to go to Victory Lane here before, but on fuel mileage.

“Today, my team, the 7 team, did a great job … Coming down to the end, I didn’t think we had a shot. I thought we were going to be top five, maybe. But those late restarts — we got great restarts … We’ve got a lot of good momentum, and, man, we want to go to Homestead and pull home this championship.”

As Allgaier made the most of his opportunity, his most formidable competitors suffered from self-inflicted wounds. Jones, who led 94 laps, and Blaney, who led 28, both drew pit-road speeding penalties under caution during the break between the second and third stages and had to fight to regain track position.

Erik Jones, driver of the #20 NBA 2K18/GameStop Toyota, Daniel Suarez, driver of the #18 Comcast Business/Juniper Toyota, and Kyle Larson, driver of the #42 ENEOS Chevrolet, lead a pack of cars during the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Sean Gardner/Getty Images)

Larson’s speeding penalty on Lap 182 came too late for the driver of the No. 42 Chip Ganassi Racing Chevrolet to claw his way back to the front.

“I had a shot to win there, and I sped on pit road and had to restart in the back, behind everybody,” Larson said. “I definitely wasn’t expecting to finish second, so I’m happy about that, but a little disappointed that I sped on pit road.”

Battling to preserve a 25-point edge over Dakoda Armstrong for the last of 12 playoff berths, Gaughan slowed dramatically during the second stage as he fought to keep his No. 62 Chevrolet off the wall. But Gaughan finished the stage, eventually got his three laps back — thanks to three cautions in the last 50 laps — and qualified for the Playoffs.

“I think the last time I had an equalized tire was in Winston West racing,” Gaughan said. “Man, we held on for dear life for that session. Three more laps, and I’ve got a top-10 out of it!

Elliott Sadler, driver of the #1 OneMain Financial Chevrolet, celebrates winning the regular season championship with a burnout following the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Jonathan Daniel/Getty Images)

“We don’t quit. We never quit. No matter what the circumstances, we do not stop, and today was just another example of that.”

Rookie Cole Custer led a career-best 41 laps and took seventh place.

The XFINITY postseason opens with the series’ next race, scheduled next Saturday at Kentucky Speedway (8 p.m. ET, NBCSN).

Rookie William Byron, a three-time winner this year, was hampered by transmission trouble, necessitating a pair of stays in the garage for repairs. He finished 34 laps down in 33rd place, but enters the final seven races as the Playoffs’ top seed.

Note: The No. 98 Ford driven by Darrell Wallace Jr. was found with one non-secure lug nut in post-race inspection.

For race results, click here.

Media Center Interviews:

Justin Allgaier – 

Kyle Larson – 

Daniel Hemric – 

Elliott Sadler – 

Jason Burdett and Dale Earnhardt Jr. –

Elliott Sadler, driver of the #1 OneMain Financial Chevrolet, and his crew chief Kevin Meendering pose for a photo opportunity with the regular season championship trophy following the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. (Photo by Jared C. Tilton/Getty Images)

Daniel Hemric, driver of the #21 Blue Gate Bank Chevrolet, Michael Annett, driver of the #5 Pilot Flying J Chevrolet, Brendan Gaughan, driver of the #62 South Point Hotel & Casino Chevrolet, Elliott Sadler, driver of the #1 OneMain Financial Chevrolet, Blake Koch, driver of the #11 LeafFilter Gutter Protection Chevrolet, Cole Custer, driver of the #00 Haas Automation Ford, Justin Allgaier, driver of the #7 BRANDT/Celebrating the Future of AG Chevrolet, William Byron, driver of the #9 AXALTA/JamesHardie Chevrolet, Brennan Poole, driver of the #48 DC Solar Chevrolet, Jeremy Clements, driver of the #51 RepairableVehicles.com Chevrolet, Ryan Reed, driver of the #16 Lilly Diabetes Ford, and Matt Tifft, driver of the #19 TMNT Lone Rat & Cub/ABTA Toyota, pose for a photo opportunity following the NASCAR XFINITY Series TheHouse.com 300 at Chicagoland Speedway on September 16, 2017 in Joliet, Illinois. Sean Gardner/Getty Images