Kyle Larson and Kevin Harvick hate late-race cautions.

William Byron loves them.

After a two-tire call under the fourth caution flag in Sunday’s United Rentals Work United 500 at Phoenix Raceway, Byron surged past Hendrick Motorsports teammate Kyle Larson in overtime to win his second straight NASCAR Cup Series race.

Byron can thank Ford drivers Aric Almirola and Harrison Burton, who on successive weekends spun with a handful of laps left—at Las Vegas and Phoenix, respectively—and gave Byron a chance to capitalize on the opportunity.

As a result, Byron had his second victory of the season and a guaranteed ticket into the Cup Series Playoff. The driver of the No. 24 Chevrolet won for the first time at Phoenix and for the sixth time in his career.

Byron credited crew chief Rudy Fugle with the two-tire call that got him out front with a chance to win.

"Owe the last couple weeks to him," said Byron, who also won at Las Vegas on two fresh tires. "He’s done a really good job strategy-wise, and execution-wise we’ve done a good job to put ourselves in those positions on the front row with a shot at the end.

"Thanks to everybody back at Hendrick Motorsports, putting together great cars, doing a great job.This is a big credit to them, engine shop, (team owner Rick) Hendrick, everybody."

Harvick leaves his best track with a mountain of frustration as tall as spectator-friendly Rattlesnake Hill at the east end of the 1.0-mile speedway. That he posted his 20th straight top 10 at Phoenix—a NASCAR Cup record for a single track—was of scant consolation.

"It’s what I would have done," Harvick said of crew chief Rodney Childers’ four-tire call. "I’d always rather be on offense. I just didn’t get a couple cars when that first caution came out. Kind of lost our chance. Still thought I had a chance there at the end. Those cars were quite a bit slower. They get all jammed up.

"That’s the way it goes. Just smoked ’em up until the caution. They did a great job with our Hunt Brothers Pizza Ford Mustang. Didn’t need the caution at the end."

Harvick had a commanding lead when Burton spun at the start/finish line on Lap 302 of 312. Harvick took four new tires on the ensuing pit stop but came out seventh behind Larson, Byron, Ryan Blaney, Ross Chastain, Kyle Busch and Denny Hamlin—all of whom opted for two tires.

Larson took the lead on a Lap 310 restart, but an accident on the backstretch involving Noah Gragson, Ty Gibbs and AJ Allmendinger forced overtime, and Byron grabbed the lead after the restart on Lap 316.

Blaney and Tyler Reddick, who had taken four tires, also got past Larson during the two-lap overtime to finish second and third, with Larson holding fourth. Harvick came home fifth after leading 36 laps.

For the first two stages, it appeared Larson and Byron would decide the race between them. Byron grabbed the lead from his teammate on Lap 2 and held it thought the end of Stage 1 on Lap 60. During the stage break, Larson regained the top spot under caution, taking advantage of the No. 1 pit stall he earned for winning the pole on Saturday.

Larson dominated the second stage on the way to leading a race-high 201 laps. But Harvick beat Byron off pit road for the second position during the Stage 2 break and kept Larson in his sights. After an exchange of green-flag pit stops that saw Harvick gain considerable ground, Harvick closed on Larson.

With NASCAR’s new lower-downforce competition package in use for the first time, the driver of the No. 5 Chevrolet struggled in traffic, and Harvick closed in. When Larson had difficulty passing Justin Haley and Austin Cindric in succession, Harvick was on his bumper.

On Lap 269, Harvick made the pass for the lead and pulled away to an advantage of nearly four seconds before Burton’s spin slowed the field.

Though Larson held the lead after one late restart, the second time proved the charm for Byron. For the second straight week Larson was frustrated. At Las Vegas, he lost a big lead when Almirola hit the wall. At Phoenix, he was mad at himself.

"Restarts are just tough," Larson said. "I felt like I ran William up pretty high. I was expecting him to lose some grip. But he did a really good job of holding it to my outside, clearing me down the back.

"Yeah, I’m pissed off. Great fight by the team, great car—way better than we were here last year. Yeah, I mean, it’s a long season, but hopefully we’re in the Final 4 (Championship 4 race) when we come back here in November and can have a run similar to that with speed and try to execute a little bit better at the end."

Christopher Bell ran sixth, and defending race winner Chase Briscoe finished seventh after a slow start. Kyle Busch was eighth, and Hendrick drivers Alex Bowman and Josh Berry (subbing for injured Chase Elliott) were ninth and 10^th.

Chevrolet drivers have won all four Cup races this season.