CHICAGO — There were accusations of dirty driving, team owners nearly came to blows, and that was before Tony Kanaan delivered these fighting words on Friday.

“If we get in a fistfight this weekend, don’t be surprised,” he said.

OK, he was just joking.

The IRL has seen plenty of drama the past few weeks, and it will culminate when Indy 500 winner Dario Franchitti tries to hold off Scott Dixon and Kanaan for the championship at Chicagoland Speedway on Sunday.

Franchitti leads with 587 points, three ahead of Dixon heading into the PEAK Antifreeze Indy 300. The surging Kanaan (548 points) has won three of the past four races and leads the IRL with five wins this season, but he would need a victory and help to capture his second championship.

“The battle has been so intense,” said Franchitti, seeking his first title.

And it has left behind a long line of accusations the past few weeks, starting at Sonoma on Aug. 26 and continuing at Detroit.

At Sonoma, Dixon took the points lead when Franchitti crashed with teammate Marco Andretti late in the race, leaving Franchitti fuming on pit road. He criticized Andretti, who returned the favor. And Andretti Green Racing co-owner Michael Andretti defended his son, saying Franchitti should have been more patient.

Meanwhile, Andretti Green’s Kanaan angered Dixon and league officials by laying back late in the race and refusing to pass Franchitti, preventing his teammate from losing points. That also set off legend Rick Mears, who said those tactics damage the sport’s credibility.

A week later at Detroit, there were more plot twists.

Kanaan won the race to jump into mathematical contention for the championship and sarcastically dedicated his victory to Mears.

Buddy Rice ran out of gas near the end of the race, setting off a wild chain of events. After running into Rice, Dixon’s car spun across the track in front of Franchitti, causing another collision on the last lap.

Although Franchitti managed to finish and retake the points lead, Michael Andretti was so enraged that he and co-owner Kevin Savoree had a heated confrontation with Dixon’s owner, Chip Ganassi. Michael Andretti thought the crash was deliberate, even though Dixon said it was accidental and Franchitti said he believed him.

But there was no evidence of ill will as Franchitti, Dixon and Kanaan chatted over burgers and fries at the ESPN Zone on Friday.

Dixon joked that all the drama was “for TV ratings. That’s why we do it.”

Kanaan said in jest, “We’re here pretending that we like each other,” before turning serious.

“We go back a long ways,” he said. “We’ve been racing together for almost 10 years. We do get frustrated. We do talk about what happened afterward. But I think there’s such a high level of respect that I think we’re beyond that, we’re bigger than that.”

And Franchitti insisted there are no lingering bad feelings — with the other drivers or the Andrettis. He said he and Marco Andretti cleared the air after the Sonoma race, and he and Michael Andretti did the same over dinner after Detroit.

Dixon, who won at Sonoma, even defended Kanaan’s decision to lay back in that race, saying, “Anyone in that situation would do the same thing.”

And Kanaan said, “I think Scott had all the reasons to be upset in a certain point, but in the end, he ended up winning the race anyway.”

Kanaan was miffed at Mears and wondered if the racing legend’s association with Penske Racing fueled the criticism.

“Rick Mears made it sound like I held (Penske driver Sam Hornish Jr.) up,” Kanaan said. “Hornish wasn’t a contender in that race — ever — apart from one yellow. It’s not that Sam fought for the lead with me and Scott the whole race and I blew his chances.”

All the recent episodes seemed to obscure the fact that the championship will be decided at Chicagoland, just as it was last year. And the driver with the most wins barely has a shot.

Kanaan needs to win the race, lead the most laps and hope that Franchitti finishes no higher than 16th and Dixon no better than 13th.

“It’s been a long year, and the competition has been very tough,” said Dixon, the champion in 2003 and a four-time winner this year. “The competition’s been very tough. There’s a lot of weight on your shoulders. For me, it’s more important than my previous championship. The competition’s that much harder.”