LAS VEGAS (AP) Austin Dillon appeared headed to an easy victory at Las Vegas Motor Speedway until four fresh tires helped Ryan Blaney chase him down.
Blaney charged to Dillon's back bumper and stalked him around the track for the final four laps Saturday, but a bobble ruined his momentum and allowed Dillon to wrap up the Xfinity Series win.
Dillon led 183 of the 200 laps, but Blaney made it hard for him to close out the rout.
''When you have something as good as this, you just don't want to mess it up,'' Dillon said. ''It was a heck of a last two laps. I was just trying not to overdrive and trying not to make mistakes.''
It was the third win of Dillon's career, but first since 2012, when he ran full-time in NASCAR's second tier series. Now in the Sprint Cup Series, Dillon runs only select races for Richard Childress Racing in the Xfinity Series.
He said he enjoyed racing Blaney over the closing laps for the win.
''I'm glad it ended like that, those final laps, those are the ones you remember,'' Dillon said.
Blaney, in a Ford for Team Penske, didn't think he had a shot at the win until a late call to bring him down pit road for new tires. On the fresh rubber, he was able to catch Dillon and nearly stole the win with a dramatic final two laps.
Dillon used a big block to thwart one attempt at a pass, and Blaney had just one final lap to try again. He looked high and tried to pass Dillon on the outside, but couldn't get around the Chevrolet. Then Blaney bobbled coming out of the third turn to ruin his shot at the win.
Dillon was shocked at how quickly Blaney caught him.
''The 22 put a heck of a charge on, I didn't know he had tires,'' Dillon said. ''It was like `Man, where did he come from?' It was like he had a jet pack.''
Blaney was downtrodden after the race - not over the defeat, but instead upset with himself for his involvement in an earlier accident with Erik Jones. Contact from Blaney sent Jones spinning hard into a section of wall that did not have an energy-absorbing SAFER barrier.
It was the third accident in three weeks in which a driver has hit an unprotected concrete wall. NASCAR and most of its tracks are reviewing their safety initiatives after Kyle Busch broke his right leg and left foot when he crashed into an unprotected wall in the season-opening Xfinity race at Daytona.
''It is a racing incident, but you never want to see a wrecked race car and you be a part of it,'' Blaney said. ''I don't like getting into things with people and I hate to see a race car torn up. I hate to see it. I hope he knows I feel bad about it.''
After the incident with Jones, Blaney said there was no way he would have tried to aggressively move Dillon out of his way to win the race.
''I didn't want any more people saying bad things about me after I wrecked Erik,'' Blaney said. ''No, I was not going to move him to win the race.''
Jones, who led two times for seven laps and thought he could challenge Dillon for the win, was unhappy with Blaney.
''He just lost it, obviously,'' Jones said. ''Not a lot of car control on his end today. Really unfortunate to be taken out that late. Had a strong car.''
Regan Smith finished third and was followed by Denny Hamlin, who was subbing for teammate Busch, and defending series champion Chase Elliott.
Brendan Gaughan, a Las Vegas native, finished sixth at his home track. Darrell Wallace Jr., Ty Dillon, Brennan Poole and Daniel Suarez rounded out the top 10.