Fort Worth, Texas ? Sam Hornish Jr. already had the IRL season championship wrapped up when he got to the Texas finale in 2001.

Last year, he only had to beat Helio Castroneves — which he did in an exciting 1-2 finish — after entering the last race with just a 12-point lead.

Going back to Texas this week, the IndyCar Series’ only two-time champion is again in contention with Castroneves. But Hornish is behind, and they’re not alone this time.

Five drivers can still win the title in the closest chase in IRL history. How close? If any of the top three take the checkered flag in Sunday’s Chevy 500, he wins the championship.

Castroneves and IRL rookie Scott Dixon are tied for the points lead at 467, just seven ahead of Tony Kanaan. Hornish has three wins in the last four races to get to 448 points, and Gil de Ferran, the Indianapolis 500 winner and Castroneves’ Penske teammate preparing for his last race, has 437.

“We are not going to be able to go conservative. We’re going for it,” Castroneves said.

Dixon has led an IRL-high 691 laps, 167 more than Castroneves. Dixon won his debut for Chip Ganassi’s team at Miami in March and has 10 top 10s. He’s won three times and has four second-place finishes, three of them in the last four races,.

But Dixon didn’t finish higher than 15th in the other five races — several of which he was dominating — because of crashes and mechanical problems.

“We approach the weekend the same every time. We want to win,” Dixon said. “I think the easiest way to win the championship is going to be to win the race. This season has been so intense.”

Helio Castroneves celebrates winning the IRL Gateway 250. Castroneves, who won the race Aug. 10 in Madison, Ill., is one of five drivers in contention for the IRL points title.

Dixon will be trying to give Ganassi his first IRL title. The team won four straight CART championships.

Castroneves has 11 top 10s, finishing eight races in the top three spots. His two wins came during the three August races, before a gearbox failure led to a costly 20th-place finish at Chicago.

Roger Penske has 11 open-wheel championships, but like Ganassi hasn’t won an IRL title. Castroneves and de Ferran finished 2-3 for Penske last year in the owner’s IRL debut.

Castroneves or Dixon can finish as low as 21st place and still win the title, depending on where the other contending drivers finish.

Kanaan hasn’t been back to the winner’s circle since the second race of the season for Andretti Green Racing. But he has 11 other top-10 finishes and control of his championship dream.

Hornish, moving to the Penske team as Castroneves’ teammate next season, hopes to end his three-year run with Pennzoil Panther Racing by winning his third straight fall race at Texas — and the team’s fourth. That could result in an unprecedented third straight IRL title.

De Ferran, who won consecutive CART titles before Penske’s move to the IRL, is retiring from the cockpit after Texas. He’s trying to focus on racing rather than retirement, knowing he has to finish first or second for a chance at going out with a title.

“Ultimately for me, my chance to win the championship depends on everybody else’s results,” he said. “I’m concentrating on the job ahead rather than get all emotional about this being my last race.”