William Byron has a penchant for milestones, and in Sunday’s Cook Out 400 at Martinsville Speedway, he got another.

Last year Byron picked up the 300th NASCAR Cup Series victory for Hendrick Motorsports at Texas Motor Speedway.

On Sunday, in a race that went to overtime, Byron led an unprecedented 1-2-3 finish for owner Rick Hendrick at the 0.526-mile short track, as the organization celebrated its 40th anniversary in NASCAR’s premier division.

In front of a throng of employees and supporters gathered in tents overlooking Turn 2, Hendrick became the only organization to sweep the podium positions in a Cup race at Martinsville. Byron’s victory was the 29th for Hendrick Motorsports at the track, most for an organization at a single NASCAR venue.

“Just so proud of everyone at Hendrick Motorsports,” Byron said. “Grew up a big Hendrick fan. To be here for the 40th anniversary, all that goes into just this organization, all the people, it’s all about the people. Just want to thank Mr. Hendrick and (wife) Linda and everyone involved.

“It’s pretty awesome. Bad-ass to win at Martinsville. We’ve been struggling at the short tracks. Just kept inching up on it. I’ve got a great team. They just kept my head in it. It stunk to do a restart there at the end like that, but that’s the way it goes.”

An early green-flag pit stop proved the difference for the driver of the No. 24 Chevrolet, who earned his third victory of the season, his second at Martinsville and the 13th of his career.

With Denny Hamlin in the lead, crew chief Rudy Fugle called Byron to pit road on Lap 297 as the first of the lead-lap drivers to get fuel and fresh tires. Hendrick teammates Kyle Larson, the pole winner, and Chase Elliott followed a lap later.

The early stops allowed the Hendrick drivers to leap-frog Hamlin, who pitted on Lap 299 and could not advance past the fourth position before caution for John Hunter Nemechek’s accident in Turn 4 on Lap 398 of 400 sent the event to overtime.

On Lap 310, Byron passed Elliott for the ninth position, and as the drivers ahead of him made pit stops, he worked his way forward, passing Daniel Suarez for the lead on Lap 327 before Suarez came to pit road.

Byron led the next 86 laps, and after Elliott was credited with leading Lap 413 at the overtime restart, Byron surged ahead for the final two circuits and crossed the finish line 0.550 seconds ahead of Larson.

“Congrats to William,” said Larson, who won the first 80-lap stage wire-to-wire. “He did a really good job. Kind of schooled us all there after that green flag stop. Did a really good job passing all of us. He was able to set a good pace, still get through traffic good.

“My car felt really good. I think we were all kind of the same speed, honestly. Just lost a little bit of track position there in the second stage. Was never able to overcome it.”

Byron held a lead of more than two seconds before the fifth and final caution of the race. On the overtime restart, he survived a bump from Elliott, who slipped to third behind Larson at the finish.

Bubba Wallace ran fourth, followed by reigning series champion Ryan Blaney. Joey Logano, Tyler Reddick, Alex Bowman, Ryan Preece and Chase Briscoe completed the top 10. Hamlin pitted for fresh tires before the overtime, restarted 10th and came home 11th.

“We were just trying to do anything we could to steal one with our Sport Clips Toyota,” Hamlin said. “The tires didn’t wear enough to matter. We saw that when Joey (Logano) stayed out on those 80-lap lefts and led most of the stage (Stage 2).

“Tires didn’t wear, and we just struggled to pass all day. Once I came out of that cycle, third or fourth, that’s kind of just where I stayed.”

Larson, who led 86 laps, took over the series lead by 14 points over Martin Truex Jr., who finished 18th on Sunday, and by 17 over Hamlin.

The only negative aspect of the Hendrick party was the absence of the team owner, who underwent knee replacement surgery and couldn’t attend. But NASCAR Hall of Famer Jeff Gordon was there to serve as grand marshal and represent the organization.

“These guys, these three guys, as well as Bowman, they drove their butts off,” Gordon said. “How about that William Byron, the 24 car? Every time we have a milestone day or opportunity or moment, he steps up.

“He got number 300. This is going to be a huge win for him and the whole organization.”