Martin Truex Jr. went from a completely unraveled tire that left him a lap down to the NASCAR Chase for the Sprint Cup championship lead for the first time in his career.

He can thank a late caution in what has been an emotional year for the small-team driver.

Truex shot to the front after a late re-start and pulled away to give Furniture Row Racing a NASCAR Sprint Cup playoff-opening victory Sunday at Chicagoland Speedway.

"I've had a lot of practice at it,'' Truex said about the on-track obstacles.  "I think my approach really changed two years ago when (girlfriend) Sherry got diagnosed with cancer. My approach to all those things changed and made me a better driver.''

NASCAR announced after the race that Truex's No. 78 Toyota failed the laser inspection, but the infraction was not at the level of negating the victory for Chase qualification purposes. Truex is expected to receive a point penalty this week.

Rookie Chase Elliott appeared on his way to an easy win until Michael McDowell blew a tire and spun out to bring a caution with five laps left.

Elliott and Truex came in to pit for tires, with some non-Chase drivers Ryan Blaney and Kasey Kahne and Chase contender Carl Edwards staying on the track.

Truex restarted fourth and Elliott fifth, and Truex quickly got to the front and held off Joey Logano on the final lap for his third victory of the season. Truex is guaranteed to move on when the Chase field is cut from 16 to 12 in two weeks.

Truex, whose team gets technical support from Joe Gibbs Racing, made the last four in the 2015 Chase. His 2016 season started with near miss at the Daytona 500 and a Coca-Cola 600 win, while Sherry Pollex has battled ovarian cancer. She's now in remission.

"You have to understand, this isn't the end of the world.'' Truex said of racing setbacks.  "We can overcome it. That's what we did today.''

Elliott, a rookie, finished third, followed by Blaney and Chase driver Brad Keselowski, who sits second in points.

"It's not yours until it's over,'' the 20-year-old Elliott said.  "That's part of life, man. You're not dumb. We've all watched this stuff long enough to know these races don't go green that long.''

Truex led early in the race only to have his tire come completely unraveled. It led to an unscheduled stop that left him a lap down in the 400-mile race.

"The hard compound came off it,'' Cole Pearn, Truex's crew chief, said.  "I guess (Goodyear) saw a couple other tires and came down and told us a certain sequence number had an issue.''

Truex had no other tire issues on the 1.5-mile oval and outraced Kevin Harvick, who also got into early trouble, to be in position for the free pass to the lead lap on the next caution.

Jimmie Johnson dominated the middle of the race, leading 118 laps, until Elliott got by him on lap 176 of 267.

Johnson was running second when he was caught speeding on pit road during the last green-flag stop, yelling ``no way!'' on his radio when told he had to serve a pass-through penalty. Johnson finished 12th, but his car also failed laser inspection and he could plummet in the points standings.

Elliott led for 75 laps in what was a clean race with only three cautions until McDowell's late wreck changed the dynamic of the race.

"I feel for Chase. I know what he's going through,'' Truex said. ``I wasn't going to catch him.''

WHO'S HOT: Chase drivers Truex, Logano, Elliott, Keselowski, Denny Hamlin, Kyle Busch and Matt Kenseth all finished in the top 10. Jamie McMcMuray was 11th, Kurt Busch 13th, Austin Dillon 14th, Carl Edwards 15th and Tony Stewart 16th.

WHO'S NOT: Kyle Larson, who had the fastest car in Saturday's practice, had to change a transmission and start from the back. He finished 18th. ... Harvick ended up 20th amid multiple issues. ... Rookie Chris Buescher fell a lap down 41 laps in and two laps down before the 100th lap. He finished 28th.

PENALTIES: Based on new rules announced last week, Johnson could receive a 10-point penalty, which would drop him into a tie for 12th in the Chase standings. Truex could be docked 15 points, but the win locks him into the second round.

DILLON SUBS: Ty Dillon finished 27th filling in for Regan Smith in the No. 7 Chevrolet. Smith left the track Friday and returned to North Carolina after his wife went into labor.

COWABUNGA: With Nickelodeon the race sponsor, the winning trophy was a gold base with the four Teenage Mutant Ninga Turtles on top in various poses. Truex plans to put it in his shop so visiting kids can get a picture with it.

UP NEXT: Two races remain before the Chase field is cut to 12. Next Sunday is a 300-mile race at New Hampshire, where Kenseth won in July.

AP-WF-09-19-16 0013GMT