Klaus Graf, CytoSport Porsche, Mosport Park 2010CytoSport took its first American Le Mans Series pole at Mosport Park as Klaus Graf beat Dyson's Chris Dyson and Highcroft's Simon Pagenaud in a thrilling qualifying battle.

Although Le Mans winner and Porsche factory driver Romain Dumas is in the CytoSport Porsche this weekend in place of injured owner/driver Greg Pickett, the team entrusted regular driver Graf with qualifying duties - and he did not disappoint.

In the opening minutes he swapped pole with Highcroft HPD driver Pagenaud twice before Dyson found more speed in his family team's Lola-Mazda and nosed ahead of them both.

But Graf dug deep and became the only man to break into the 1m06s in the session as he claimed pole halfway through the session by 0.2sec over Dyson. The American pushed on trying to regain the spot before having to settle for second when Johnny Mowlem's Autocon Lola stopped in a dangerous place, prompting a red and eventually a checkered flag.

Behind Pagenaud, Elkhart Lake winner Drayson Racing's pole run came to an end as Jonny Cocker could only manage fourth in the Lola coupe.

Gianmaria Bruni gave Risi Ferrari another GT pole but is set to start at the back as the team was forced to change its driver lineup when Jamie Melo was struck down with a stomach virus. Toni Vilander has been brought in from the sister car to partner Bruni instead - the Finn's team-mate Pierre Kaffer having had a massive crash in practice that damaged their 430 GT beyond immediate repair and sent the German to hospital for precautionary checks. Fortunately he escaped injury.

The Risi demotion will hand pole to the #45 Flying Lizard Porsche driven by Jorg Bergmeister in qualifying. Tommy Milner's Rahal Letterman BMW was next up in the session, followed by the Corvette now shared by Oliver Gavin and Jan Magnussen. A team shakeup for this weekend has seen Magnussen brought into the #4 entry alongside Gavin while Olivier Beretta moves in the opposite direction to join Johnny O'Connell in the #3.

In the one-make divisions, PR1/Mathiasen driver Luis Diaz topped LMPC again, and Orbit's Bryce Miller inflicted a rare GTC qualifying defeat on Jeroen Bleekemolen.