William Byron added to his season highlight reel earning his first career NASCAR Cup Series road course victory with a dominant win in Sunday’s Go Bowling at The Glen at historic Watkins Glen (N.Y.) International.

It marks a career best fifth victory of the season – tops in the NASCAR Cup Series and most for him in a single season in a six-year career in NASCAR’s top series. And the 25-year-old Charlotte native and driver of the No. 24 Hendrick Motorsports Chevrolet had to earn this one – holding off another championship challenger, Denny Hamlin by a healthy 2.632-seconds for the win. Byron led an impressive 66 of the 90 laps – extending his advantage over the field each lap of the final 10 lap-run to the checkered flag.

“Yeah, I would have to think about that a little bit though,’’ Byron said when asked if he felt like it was his most dominant race win. “But it definitely feels really good, just a huge credit to the race team behind me. I want to thank Max Papis. My first road course win and we worked years and years for this.

“Thanks to all the guys on the team. I did a lot of laps on iRacing this week, got a new simulator at home. It’s a great win. It shows when we’re at our best we can perform like this.’’

Byron, who won Stage 2 on Sunday, noted the timing is important as the series heads into the Playoffs.

“We seem to go through that summer slump in July and August and for some reason we just can’t put the races together, I think it’s the race tracks themselves. But this weekend, we came with a good mindset and focused on getting ready for the postseason. We’ve had fast cars just haven’t executed races, but today was flawless.”

Hamlin’s runner-up finish keeps the NASCAR Cup Series regular season championship still up for grabs. He trails his Joe Gibbs Racing teammate Martin Truex Jr. – who finished sixth – by 39 points heading into next week’s Daytona regular-season finale.

Joe Gibbs Racing driver Christopher Bell finished third with Kaulig Racing’s A.J. Allmendinger and JGR’s Ty Gibbs rounding out the top five.

Truex, Roush-Fenway-Keselowski Racing’s Chris Buescher, 23XI Racing’s Tyler Reddick, Team Penske teammates Ryan Blaney and Joey Logano rounded out the top 10.

With finishes of 15th and 21st, respectively, Roush-Fenway-Keselowski Racing owner/driver Brad Keselowski and Stewart-Haas Racing driver Kevin Harvick both locked themselves into the 2023 Playoffs based on points. That leaves only one position to be decided in next Saturday night’s regular season finale at Daytona International Speedway.

23XI Racing’s Bubba Wallace solidified his hold on that all-important 16th place in the points standings that could automatically transfer him into his first Playoff berth. Although Wallace concedes road course racing is not his strongest suit, he did exactly what he needed to, turning in a non-dramatic, consistent day. Wallace, who said he had a valuable phone conversation with six-time IndyCar Series champion Scott Dixon before the race, earned points in both stages. And his 12th place finish was his best road course finish of the five run so far this season.

He now holds a 32-point advantage on the Joe Gibbs Racing rookie Gibbs and a 43-point advantage on Trackhouse Racing’s Daniel Suárez.

“Just executed really,’’ Wallace said, noting that no new race winner Sunday certainly helps his cause in pursuing his first ever Playoff berth.

“I’m proud of myself and that’s the first time I’ve felt proud of myself after a road course race. Just executed and didn’t lose focus, maybe one time. And that’s the difference-maker. You’ve got to stay on it in these places. Hats off to my team for sticking with me and believing in me.

“Great day for the 23-team,’’ he added. “Now we get to go into Daytona, still stressful as hell but it takes a little bit of the edge off.’’

On the flip side of fortune, it was a troublesome day for two of the other high-profile teams still needing to race their way into the upcoming Playoffs and needing a race win.

Hendrick Motorsports’ Chase Elliott – the five-time and reigning Most Popular Driver in the NASCAR Cup Series – came into the race already depending on a high speed Hail Mary of sorts. He was 80 points behind Wallace at the green flag. But Elliott’s team was slowed by an uncharacteristic fuel miscalculation. His No. 9 Hendrick Motorsports Chevrolet ran out of fuel with 23 laps remaining, stopped on-course and brought out a caution flag to push him back to pit road for a fuel-up.

Elliott returned to race a lap down and finished 32nd and is now 21st in the standings.

The three-time Daytona International Speedway polesitter will need to earn his first win at the superspeedway to advance to the Playoffs this season and keep his eight-year run of championship eligibility going. Elliott has two runner-up finishes at Daytona, in the 2020 summer race and the 2021 DAYTONA 500. He finished 29th in the summer race there last season.

Elliott wasn’t made available to comment after the race.

“That’s sort of the agony of a four-car team when one car does so well,’’ Hendrick Motorsports executive Jeff Gordon said of the day at The Glen. “It just shows you can’t make any mistakes.

“Unfortunately, we had some mistakes,’’ he added, “Clearly it was a mis-calculation with the 9 car [Elliott] and that was huge.”

Trackhouse Racing’s Daniel Suárez started the day only one position out of the top 16 – 28 points behind Wallace. But Suárez was the first of those on the Playoff bubble to encounter issues – going off-course at the famous “bus stop” portion of the Watkins Glen course and brushing the wall only five laps into the race.

The off-course excursion dropped him from 10th place at the time to 24th in the field and he had to play catch-up all day, ultimately finishing 22nd. He goes into the Daytona season-finale next week 43 points out of the top 16 and also needing a victory.

The rookie Gibbs actually improved his standing among those still within Playoff reach as the regular season closes. The driver of the No. 54 Joe Gibbs Racing Toyota – who led a race best 70 laps in Saturday’s NASCAR Xfinity Series race at Watkins Glen – ran among the top five all Sunday afternoon as well. His fifth place finish Sunday was best among those in the close fight for a Playoff berth. He goes to Daytona Beach 32-points behind Wallace and needing a win.

“I felt like we were really fast,’’ the 2022 NASCAR Xfinity Series champion Gibbs said. “I just didn’t do a good job of getting through the guys in front of us. I feel like we were much faster than three of them in front of us and I just couldn’t get by them.”

Of his move into 17th place in the standings, and placing himself on the cusp of a Playoff berth, Gibbs said, “I don’t really know what mindset to have going there just to stay clean and try to make it to the end and have a good finish.’’

The NASCAR Cup Series regular season finale to set the 2023 16-driver Playoff field takes place at the Daytona International Speedway with Saturday night’s ’s Coke Zero Sugar 400 (7 p.m. ET, NBC, MRN, SiriusXM NASCAR Radio). Austin Dillon is the defending race winner. Ricky Stenhouse Jr. won the DAYTONA 500 in February.