JOLIET, Ill. — Justin Allgaier threw a victory bash in front of his home-state fans.

Allgaier pulled away off the final restart and won the NASCAR Xfinity Series race Saturday at Chicagoland Speedway.

Allgaier, from nearby Riverton, won for the second time this season in NASCAR's second-tier series. JR Motorsports had a banner day with Allgaier's win and the official coronation of Elliott Sadler's regular-season championship.

"This is a race track I've loved dearly for a number of years," Allgaier said. "The whole connection of being from Illinois and getting to go to victory lane was incredible."

William Byron and Michael Annett give JR Motorsports four drivers in the Xfinity Series playoffs. Byron, who will replace Kasey Kahne in the No. 5 car next year at Hendrick Motorsports, enters the post-season as the points leader.

"If we have the opportunity to compete against each other at Homestead, once the green flag drops, it's every man for himself," Dale Earnhardt Jr. said.

Xfinity opens its post-season next week at Kentucky Speedway.

The rest of the playoff standings look like this: Allgaier, Sadler, Daniel Hemric, Brennan Poole, Ryan Reed, Jeremy Clements, Cole Custer, Blake Koch, Matt Tifft, Brendan Gaughan and Annett.

Byron has three wins this season and should be the driver to beat in the seven-race post-season. But his No. 9 Chevrolet battled transmission issues and he finished 33rd. Earnhardt said he wasn't picking a favourite among his championship drivers.

"These guys work really well together," Earnhardt said. "The crew chiefs all have a close relationship that goes beyond JR Motorsports. I think that's why we're so successful, because of the way they work together."

Cup regular Kyle Larson was second at Chicagoland.

"I was too loose to keep pace," Larson said.

The 42-year-old Sadler has finished second in the final standings three times over an Xfinity career that dates to 1995. He thought he had the car to beat headed into last year's season finale at Homestead-Miami Speedway until his crew chief was suspended for the race. Daniel Suarez would become NASCAR's first Mexican champion.

"I felt like last year, my team was primed and ready to go," Sadler said. "Then we lost our crew chief for Homestead and that made it a lot harder to try and be as competitive. I think the difference is to make sure we get through the playoff with no mistakes, no issues."

Erik Jones started from the pole, led 94 laps and was in position to win the race until he was penalized for changing lanes before he reached the start-finish line with seven laps left in the race. Jones finished 18th.

Allgaier benefited in the No. 7 Chevrolet from Jones' mistake and won at Chicagoland for the second time in his career.

"This one, the meaning of it is a lot greater," Allgaier said. "When we got to the point where we took the white (flag), the emotion just flooded over me and it was just incredible."

Allgaier's parents, in-laws, cousins and other friends and family celebrated with him in the post-race party. But the moment was truly capped when his 4-year-old daughter was with him for the first time in victory lane.

"I hope she realizes at an older age just how special that moment is," he said.

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