Sebastien Bourdais took his fifth victory of the Champ Car season to extend his lead at the top of the drivers standings after a stunning drive in the Grand Prix of Denver.

The Frenchman was involved in an incident at the first corner that dropped him down the order, before he produced an assured drive to hit the front in the closing stages of the race.

Starting from pole position, Bourdais headed into the first corner battling for position with Newman Haas teammate Bruno Junqueira, only for the two touch as the Brazilian tried to take the lead round the outside. While he was able to continue in the lead, Bourdais span, dropping down the field to 13th.

Also in trouble at the first corner were Alex Tagliani, Rodolfo Lavin and Nelson Philippe, making a return to the series with Mi-Jack in place of Alex Sperafico. The trio tripped over each other at the start and five cars were forced to pit at the end of the first lap as the race ran under a full course yellow.

Having kept his car pointing the right way, Junqueira held first place as the race went green with reigning series champion Paul Tracy following in second and Patrick Carpentier up into third, narrowly ahead of Mario Dominguez.

As Junqueira slowly eased out a small gap over Tracy, the man on the move was Bourdais. By lap ten he had made it upto eighth, and was into the top five by the time the first pitstops were made.

Those first pit stops saw the second lead change of the day as Tracy was able to save enough fuel to allow his Forsythe Championship Racing team to get him out in front of Junqueira on lap 40.

Tracy would hold the lead for the next 40 laps and appeared to have things well in hand as he chased the win. Dominguez was only four seconds off the lead after making an inside pass on Junqueira in turn five, a move brought about as Junqueira was suffering brake problems with his car.

Bourdais meanwhile had beaten Oriol Servia out of the pits on his stop to claim fourth, before he too found a way past Junqueira to take the final place on the podium. However, he was still eleven seconds behind the leaders with 25 laps to go.

Salvation came in the form of a Ryan Hunter-Reay spin on lap 73 as the yellow flag waved to bunch up the field while Hunter-Reay's stricken car was towed out of turn nine.

With his advantage gone, Tracy lined up ahead of Dominguez and Bourdais on the lap 79 restart, but the Newman Haas man didn't wait long to make a move as the race went green.

Bourdais went inside Dominguez into turn one, surviving a brief bit of wheel banging to take the second spot.

Two laps later and, when Tracy miscued on braking, Bourdais pounced to make the pass into turn nine to hit the front, pulling away from the Forsythe car to finish seven and a half seconds ahead, despite picking up minor damage to the suspension as a result of his pass on Dominguez.

"It is a beautiful win today," a delighted Bourdais said afterwards. "To start on the pole, then it was difficult to work your way back to the top, and win, it is a great feeling. I had to pass guys on the track and earn my way back to the top, and we were able to do that in the McDonald's car. When I was running in fourth, I realised I could possibly win this, but it was not going to be very easy. This is the best street race in a long time and it is a terrific weekend. I am very, very happy."

Tracy settled for second with Junqueira rounding out the podium in third, despite the pair leading for a combined total of 79 of the 90 laps.

Despite missing out on victory, Tracy wasn't in the mood for complaining.

"It went better I expected," he said. "The car was not handling well. I thought that we had the race until the yellow came out. The car was ok, but it was not that fast. It was adequate enough to keep a consistent pace.

"The Indeck team did a great job on the first stop allowing me to get out ahead of Bruno. There was not much I could do when Sebastien came up behind me. I gave way to him, he had a better car then I did. I just wanted to be sure to have a good finish. This was definitely one of the best street course races we have had in a long time and it was definitely a good show."

Dominguez took fourth spot, with rookie points leader A.J. Allmendinger scoring his third top-five finish of the season as he brought his RuSPORT machine to the line in the fifth spot. With closest rival in the standings Justin Wilson two places further back, Allmendinger now holds a 13 point lead in the battle to be crowned top rookie.

In between the two rookies, Orial Servia battled back from a stuck air jack that caused his car to smoke under braking for the last 20 laps to take sixth, Mario Haberfeld finished eighth while Patrick Carpentier battled handlings problems on his way to ninth. After two early pitstops as a result of the first lap incident, Road America winner Tagliani rounded out the top ten.

The series takes a week off before heading to the Canada for the Molson Indy Montreal at the end of the month, with Bourdais looking in ominous form at the top of the standings.

His lead over the field is now an impressive 56 points.