Larson finally stumbles in NASCAR's championship. Was it just a bad day or sign of serious trouble?

AVONDALE, Ariz. (AP) — Kyle Larson climbed out of his beat-up No. 5 Chevrolet with a dejected look on his face, stewing about a 34th-place finish at Phoenix Raceway after a flat front right tire caused him to hit the wall.Six weeks of excellence in NASCAR's playoffs had disappeared in the span of a few miserable hours in the desert on Sunday.Even before the tire mishap, Larson struggled at Phoenix Raceway, qualifying 22nd on Saturday. He wasn't any better during the race, limping around the mile tri-oval in the back of the pack before the flat tire that almost seemed like a merciful ending.Tyler Reddick won at Phoenix for his sixth victory of the season. Ryan Blaney was second, Chase Elliott finished third and Christopher Bell was fourth.“I didn’t expect to be good, but I didn’t expect to be that bad either,” Larson said. "It wasn’t a lot of fun today, but we were just trying to salvage what we could of the day. We’ll go to Talladega and try to forget about today and get back after it.