Could a new rivalry be brewing in NASCAR?

But boy, what a battle it was to the finish between the two former champions. 

And with both drivers in their prime, it could be the start of a rivalry for the ages. 

“There's definitely some gamesmanship there, and Kyle is one of the best race car drivers out there,” Keselowski said. “He's driving for one of the best teams, and he's going to be someone that I am going to have to beat for my entire career if we're going to win races and championships.  

“I know that, and it's not something that I feel bad about. I feel good about it. I want to race guys that are great, and I think the team wants to compete against teams that are great. That's what makes this series special. That's what makes it the series that it is.”

A bad set of tires?

Over the last 100 laps, the former Cup champions traded the lead five times. Keselowski, 33, powered to the inside of Busch at the start-finish line on Lap 457 to close the deal. Busch, 31, settled for second, 1.8-seconds behind Keselowski. 

“I wouldn't have had to worry about him if I had the right tires on the car,” Busch complained. “You know, it's just a fact of the matter of when you have guys that are good and you've got guys that have fast cars, you're going to be together. Chase Elliott has been up front a lot this year, and Larson and myself, Brad, some others, as well. When you have guys that are capable of running up front each and every week, then it's going to get congested sometimes at the front, and today Brad ran a good race.

“I don't know if he knew he was better than me. He probably should have known for as bad as I was struggling in the middle of the corner and he just bided his time and waited for my stuff to finally heat up too much and he got by me  I was giving it all I had grasping for straws, just seeing if I couldn't hold him off, but I knew it was just ‑‑ time would tell.”

Busch, who started 10th, ran sixth by Lap 75 and had moved up to second at the end of the second caution on Lap 106. He settled into third at the end of the first stage and took the lead for the first (Lap 109)— and second times (Lap 136) under caution. When the race returned to green on Lap 142, after a debris caution in the second stage, Busch established himself as a contender in the STP 500.

Losing the stage win

He relinquished the lead for seven laps to Elliott then regained the point. Busch set sail for 108 laps — the most dominant run of the afternoon. He appeared destined to win the second stage until Ricky Stenhouse Jr. gave Busch the bumper. Elliott drove to the inside for the Stage 2 win.

And Busch is well aware what those Stage Points could mean come Playoff time — particularly with the current level of competition in the Cup series. 

“Especially because we don't win races in the Chase, so definitely,” said Busch, who has only scored two of his 38-career wins in the final 10 races of the season. “That was a point that we were looking to score and try to achieve, and we lost it.  

“It's just like the rest of this year, too.  We've just thrown away points, if points matter, week in and week out.  We've just got to get ‑‑ somehow get our luck better.  I don't know what it is that just keeps knocking us back that we don't have things kind of go our way, but they just haven't been going our way, so we've just got to keep plugging along until they do.”

Elliott led 13 laps under caution, but when the race returned to green for the final stage, Busch returned to the front. He led another 64 laps before Reed Sorenson triggered the 10th caution after spinning in Turn 3. Busch pitted for the fourth time on Lap 337. He restarted third on Lap 341 behind Denny Hamlin and Stenhouse, who elected not to pit, and quickly took the lead from Hamlin before finishing the first lap of green. 

Once again, Busch took off. He led 52 laps —before making his fifth and final pit stop on Lap 394 — during the 11th caution for Jeffrey Earnhardt’s spin in Turn 2. Busch, who along with  Keselowski and Elliott, used just five tops throughout the 500-lap race, was the first to exit pit road followed by Elliott, Keselowski, Matt Kenseth and Jimmie Johnson. 

“My pit crew did great today,” said Busch, who spent the fewest amount of time on pit road among the 38 competitors. “(Crew chief) Adam (Stevens) and the guys did an awesome job on this car this weekend to get it to where it was.”

The battle for the win

Busch led the field to green on Lap 400 but was passed by Keselowski six laps later. He reported his car was plowing. Busch muscled his way past the No. 2 again on Lap 415 only to be passed by Keselowski on Lap 428. With that setback Busch asked if the tires were all the same size. Fourteen laps later, Keselowski drove by Busch for the final time for his 23rd career Cup win. 

“I thought we raced each other really well,” Keselowski said. “There were a couple of light taps, but that's short track racing, and I think that's a good thing.  

“That's what it should be, and we were able to really navigate the track well together.”

"Not finishing where we should have"

Busch blamed his lack of speed in the closing laps on his last set of tires. 

“That run it was at minimum at least three-tenths slower the entire time,” Busch said. “That’s why Brad (Keselowski) just was able to drive away there at the end. We were really, really, really struggling. I’m surprised I held off the 24 (Chase Elliott. 

“We still haven’t finished where we should have this year. We haven’t gotten any finishes that are indicative of where this team’s been running or where we’re capable of running or finishing and that’s just frustrating, so we’ll continue on.”

Keselowski scored his second victory of the season on Sunday. While Busch has yet to win in 2017, he’s picked up the pace in the last three races with top-five finishes at Phoenix and Martinsville — two tracks in the Chase — and an eighth-place run at Fontana. On Sunday, his 274 laps was a season-best and his second-place result vaulted the No. 18 Joe Gibbs Racing team to sixth in the standings. 

“Just a frustrating season so far but we give it everything we got,” Busch said. “We do all we can with what we’re given at the particular time and try to execute and do a good job.”