(AP Photo/Tim Stewart)

Saturday's LifeLock.com 400 started serenely enough, but it got crazy late with double-file restarts.

Maybe we've been looking at the wrong Busch for a rivalry in the Sprint Cup Series.

Instead of pitting Kyle Busch against Dale Earnhardt Jr. or anybody else wearing a Cup uniform, maybe we should start paying attention to the potential feud brewing between big brother Kurt and Jimmie Johnson.

They have all the ingredients to make for a humdinger. Both are champions, with Busch capturing the title in 2004 and Johnson the past three. Both are contending for a championship this season with Busch fourth and Johnson third in points following Saturday night's race at Chicagoland Speedway.

Busch has a history of being a bit temperamental and Johnson Mr. Goody Two-Shoes, so there is potential for evil versus good that always helps a rivalry even though Busch is doing his best to move to the good side.

And most important, they have issues with each other.

At least they do after Saturday.

Let's rewind. Fifteen laps remained when Busch, Johnson and Jeff Gordon went three-wide. Johnson, who lost the lead a lap earlier after Denny Hamlin got him loose on the restart, got a little loose when Gordon went underneath him.

That, Johnson said, forced him to unintentionally get into the side of Busch, who was riding on the high side of both drivers.

Busch apparently didn't see it that way. He appeared to turn into Johnson not once but twice.

Or as Johnson told reporters afterward, Busch "body-slammed him."

Terms such as body-slam also are good for rivalries, by the way.

"I don't know if it cost me the win, but he certainly body-slammed me pretty hard," said Johnson, who settled for eighth. "What's funny is that he was coming to hit me again and he saw [Gordon] on the apron and I think then he realized I didn't run him up the track on purpose.

"You know, at the end of the race everybody's tempers are high. He's one of those guys whose temper can get away from him. When he first hit me, I was like … 'This isn't necessary.' But then he backed off."

Busch was hot. He brought up an incident that happened last month at Sonoma when Johnson clipped him on Lap 90 and sent him straight into a tire barrier.

Johnson apologized immediately after the race, explaining it wasn't intentional. Case closed.

Busch isn't so sure now.

"I'm starting to lose faith in his ability to be a three-time champion on the track," said Busch, who had to pit to fix a tire rub after the incident Saturday night and finished 17th. "I'm disappointed. I gave him room and we got pounded into the fence."

While the drivers don't agree on what happened, which helps if you're starting a rivalry, they did agree that the double-file restarts contributed.

Johnson lost six spots on the restart because of Hamlin a lap before hitting Busch. That led to a brief sheet metal exchange between Hamlin and Brian Vickers, which allowed Mark Martin to cruise past everybody for his fourth win of the season.

Johnson expects double-file restarts to get even rougher the more comfortable drivers get with it and the more they learn how to take advantage of openings.

"The car, you can actually lean on each other and really make bumper-to-bumper contact on the straightaways," he said. "It's like a short track at 190 mph. It's great, but we're all getting more and more comfortable with it and pretty soon we're going to have some big pileups."

Fortunately, there's an off week for tempers to calm before the next race at Indianapolis.

Or maybe it's not so fortunate. Maybe it would be a good -- for a rivalry's sake -- thing if Johnson and Busch went back at it this weekend. There's definitely some potential here, much more than anything currently going on between the other Busch and competitors.

The other Busch finished 33rd, for the record, and has fallen all the way to 10th in the standings.

"I'm pretty livid right now, to tell you the truth," Kurt Busch said. "It's a great time to have an off week on our schedule. We'll tire test at Atlanta [Tuesday], take a breather and then come back ready to get after it again at Indy."

Nationwide Series: Kyle Busch on great streak, just not great enough for him

Six down, three to go.

Kyle Busch is marching into the history books, although probably not the way he would like to.

His second-place finish in Friday's race at Chicagoland was his sixth straight of second or better, tying him with Sam Ard for second place on the all-time list.

Jack Ingram owns the record with nine straight top-twos. He established the mark in 1983, winning twice and recording seven seconds -- including six consecutive.

Busch has two wins and four seconds during his streak. Although he's pulling away in the points standings he'd prefer to have a few more firsts.

"Second best is just that," he said after finishing behind Joe Gibbs Racing teammate Joey Logano.

Getting past this weekend's race at Gateway International Raceway in Madison, Ill., may be Busch's biggest obstacle to setting the record. He finished eighth in his last race there in 2006.

His last race at the three tracks after Gateway -- Indianapolis Raceway Park, Iowa Speedway and Watkins Glen -- resulted in two firsts and a second, albeit the first at Iowa was in a Camping World East West Series race.

Stay tuned.

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David Newton covers NASCAR for ESPN.com. He can be reached at dnewtonespn@aol.com.