Wheldon wins, Hornish champion at Chicagoland.

Sam Hornish Jr clinched his third IRL Indycar title on a tie-breaker after conceding victory in the final round of the season at Chicagoland to outgoing king Dan Wheldon.

The Marlboro Team Penske driver finished third behind a Target Chip Ganassi one-two of Wheldon and Scott Dixon, but his superior win record this season allowed him to defeat the Brit on count-back after the pair ended the campaign tied on points. Wheldon did everything he could in the race and picked up an extra three points for leading the most laps - 166 of the 200 - but Hornish knew all he had to do was sit behind the Ganassi pair and the crown would be his.

The American thus becomes the second consecutive driver to win both the Indy 500 and IRL championship in the same season, following Wheldon's dual success in 2005.

Once again the race was all about the Penske and Ganassi teams, with the latter seeming to have a slight edge around the 1.5-mile oval. No other driver even finished on the same lap as the leading quartet, a fitting tribute to a season they have completely made their own.

Wheldon, Hornish, Dixon and Helio Castroneves - the only four contenders for the title - ran at the front of the field all day, with 20 changes for the lead during 200 laps of enthralling, nail-biting action in what was the third-fastest race in IRL history.

Little over two tenths of a second separated the top three at the flag, with Castroneves a mere two seconds further back in fourth. Ed Carpenter finally emerged as 'best of the rest' a lap down in fifth place for the highest finish of his IRL career, with Vitor Meira, Tony Kanaan, Jeff Simmons, Scott Sharp and Tomas Scheckter completing the top ten.

It could all have ended so differently after team-mates Wheldon and Dixon nearly came to grief with an early brush and a spot of wheel-banging late on. They held on, though, to claim a one-two finish meaning Wheldon both started and ended the season with a victory and claimed his second consecutive win in Chicago.

The Brit will no doubt point to errors earlier in the season for his failure to retain his crown, his first having been won with Andretti Green Racing last season. He and Hornish ended the year tied on 475 points, but the American's four-win tally was double that of his rival which handed him the title, his third after two clinched with Panther Racing in 2001 and 2002.

Penske team-mate Helio Castroneves finished the season third just two points adrift, but saw his championship ambitions disappear with fourth on the road in Chicago, while Dixon finished fourth overall having had the most to do heading into the finale.

Hornish's title is a first for Penske in the IRL, the team having bounced back to the front of the field following its switch to Honda engines in 2006. Ganassi also switched from rival Toyota as the series went 'one make' and the pair dominated throughout, dividing the spoils up between them season-long.

"This is about as excited as I've ever been," a jubilant Hornish enthused afterwards. "It's been a great day for us and a great year. I wanted to win the race real bad, but I couldn't take too many chances out there.

"The season couldn't have gone much better for me. Winning the Indianapolis 500 was the highlight of my career, but this is right up there."

"It was a clean race, with lots of good racing," added team chief Roger Penske, whose outfit has won 14 Indy 500 titles in the past. "It's been a long year and a great season. We came over to the IRL to support the Indianapolis 500, and I'm glad we could win the championship. It was one we didn't have, and when you don't have something you really want it."

Wheldon was magnanimous in defeat, the reigning champion admitting he had endured too much of a troubled season to ultimately lift the crown.

"All credit goes to Roger Penske and Sam," he said. "We've had a somewhat difficult and frustrating year and this is perhaps a bittersweet end.

"It was a lot of hard work for Target Chip Ganassi Racing and the boys at Honda. This is Target's 50th win with Chip and we are happy for that.

"I was aggressive at times today, but sometimes you have to be that way. It was a good race. I was very determined to win and wasn't going to let this one get away."

Castroneves was understandably disappointed at missing out on the title after coming so close for the third time in his career. The Brazilian ended the campaign with the same number of wins as his team-mate, but his race was badly compromised after he received a penalty for speeding in the pit-lane during the first round of stops. This left him at the back of the pack and having to spend most of the remainder of the race fighting his way through again.

"I was hoping Marlboro Team Penske would be able to finish one-two in the championship," the 2002 and 2003 runner-up said. "I tried everything I could. It was very exciting out there and Sam did a great job. He's one of the best oval drivers I know."

Dixon, meanwhile, was pleased with his campaign, taking positives away from ending the season just 15 points adrift of the champion.

"It's been a good year and a good comeback for us, not just for me but for Target Chip Ganassi Racing," said the 2003 IRL champion. "I think we can take this momentum into this year.

"We seem to have the cars pretty sorted-out with moving chassis to the Dallara this season and I think we'll be pretty strong next year. It's great to end on such a high note with the team's 50th Indycar win."