FONTANA, Calif. (AP) — Austin Dillon passed Kyle Busch and Daniel Suarez on the final lap and surged to an improbable victory in the Xfinity Series race on Saturday.
Busch got within two miles of his record-tying fourth consecutive Xfinity win after leading 133 of the 150 laps, but the defending Sprint Cup Series champ blew his left front tire while attempting to save fuel.
Suarez briefly went in front while Busch attempted to keep racing on the sparking flat wheel.
But when Suarez ran out of gas, Dillon roared to his seventh career victory in his Richard Childress Racing Chevrolet in thrilling fashion.
''This is probably one of the coolest ways to win,'' Dillon said while flanked by Childress, his grandfather. ''I didn't even lead a lap today until the final one, so that's pretty cool. When you steal one like this, it means a lot more for some reason.''
Indeed, Dillon set a record for fewest laps led by a winner. He also survived a scrape with the wall on the final turn while getting around Busch, who made contact with Dillon while trying desperately to keep the lead.
Dillon was heated about the exchange after the race, but cooled down after a celebration.
''It's just racing,'' Dillon said. ''I probably would have done the same thing. ... He made the move to try to hold off, to win the race. Anybody in their right mind would have made the move. It just made the race more exciting.''
The win is another boost for Dillon, who will start Sunday's Sprint Cup Series race up front after claiming his second career pole, hoping to finish the weekend with a double from his first career Cup win.
''It definitely gives you a little bit of confidence (going into Sunday),'' Dillon said. ''You never give up in this sport, because you never know what can happen.''
Busch finished second and Darrell Wallace Jr. moved up to third, snaring his fourth career top-five finish. Suarez, Busch's Joe Gibbs Racing teammate, got home for fourth.
Busch had won every Xfinity race he had entered this season in his Toyota. He came agonizingly close to becoming the second driver in the series' history to win four straight, joining Sam Ard in 1983.
Instead, Busch couldn't claim his record 80th Xfinity win. He has still won six of the last 12 races on Fontana's weathered two-mile asphalt track, where he also won the Sprint Cup races in 2013 and 2014.
Busch was in control for most of the race, easily leading a field that included 15 drivers making their Fontana debuts. Yet he knew his fuel might barely last, and he worried even more when teammate Erik Jones ran out with three laps to go.
Dillon had his own fuel conservation worries, and he started laying off the gas several laps earlier. With a reasonable certainty he could make it, Dillon went for a win and got lucky when Busch's tire blew.
''I did my job, and sometimes things just go your way, and today it definitely did,'' Dillon said. ''Fun race. I hope the fans liked that last lap. It was exciting. A little bit of everything happened there.''
Even after a loss that left him furious, Busch's dominance of the Xfinity races has reached ridiculous proportions during NASCAR's three-week West Coast swing. He has led more laps through five races than anybody in the series' history - and he didn't even run at Daytona.
Busch led all but one lap in Las Vegas and then led 175 of 200 laps at Phoenix before leading all but 17 laps at Fontana.
Despite the thrilling finish, a Sprint Cup regular has won every Xfinity race this year. Their success has stoked criticism from hard-core race fans who dislike Cup drivers' dominance of the second-tier series.