Ryan Briscoe boosted his hopes of beating Dario Franchitti and Scott Dixon to this year’s IRL IndyCar Series title by scoring his third win of the year at the Chicagoland Speedway on Saturday. Briscoe eked out a dramatic, last-gasp victory as he and Dixon duelled side by side to the chequered flag. Running on the outside of Dixon, Penske driver Briscoe won by 0.0077sec – the fourth-closest finish in IRL history.

Talented young Brazilian Mario Moraes was third ahead of Franchitti and Graham Rahal as the leaders crossed the line in a closely-bunched pack. After 15 races Briscoe leads the championship by 25 points from Franchitti, with defending champion Dixon another eight points behind. Briscoe’s team-mate Hélio Castroneves was eliminated from the title battle when he crashed out of third after his car’s right front suspension broke.

Team boss Roger Penske congratulated Briscoe in victory circle. “What a run!” he said. “That’s the best I’ve ever seen you run. Terrific!”

Briscoe fell down the field after pulling into his pit box a few feet wide of the mark. That made it difficult for his refueller to get the nozzle properly attached, losing precious seconds. But Briscoe was able to work his way back through the field and in the closing laps he was on Dixon’s tail. Running at the bottom of the track Dixon was able to maintain a small margin over Briscoe and looked like winning until Briscoe made a late lunge.

“Coming off turn four, I didn’t think I was going to get it done,” Briscoe grinned. “But the side-draft pulled me right by. I didn’t even know if I’d won. I started screaming. I said, ‘Hey guys, did we really get it?’ It’s just awesome.

“I was doing all I could to get by Scott tonight because we don’t want him getting any more wins. He’s won enough this year.”

Dixon was disappointed to lose by such a narrow margin after leading 36 of the final 40 laps. “I’ve seen this movie several times before, unfortunately here at Chicago,” he said. “The team did a fantastic job. The pitstops were flawless. They launched me up there a few times. But we just didn’t have the speed. The domination we had last year on the mile-and-a-half tracks has really been affected this year. We need to catch up to Penske. They’re clearly a lot faster than us.”

Franchitti got stuck at the bottom of the track and couldn’t make a move in the late stages. “Scott and I worked well together helping each other pass cars,” he said. “But at the end I got caught at the bottom and couldn’t move out. If I did I would have got behind Briscoe and that would have pushed him past Scott, and there was no way I was going to push him past my team-mate.”

The Scot lost time on his last pitstop when an air gun got caught underneath his car’s nose. “I don’t know why they just didn’t pull the gun out,” he said. “That’s what costs championships right there. The Target guys did a great job up to that point and the car was pretty good, but not fast enough to win.”

Two IRL races remain, on the 1.5-mile Motegi oval in Japan on September 20 and the Homestead-Miami oval three weeks later. “We’re a little weak at the ovals and it will be hard to make it happen,” said Franchitti. “But we’ve got to keep pushing. We’re not giving up, absolutely no way.”