Colin Edwards leads Japanese Shinya Nakano practice [AFP]

The American broke Rossi's 2007 pole record by nearly three tenths of a second with a late lap of 1 minute, 58.139 seconds, almost four tenths ahead of the Italian.

The front row will be completed by reigning Moto GP champion Casey Stoner of Ducati, with the Australian reaching the front three for the first time this season.

Championship co-leader Jorge Lorenzo was fourth quickest, bravely returning to the saddle after a spectacular crash in practice on Friday that left him with a chipped bone in his left ankle and severe bruising to his right leg.

The Spaniard had to be helped on and off his bike by his crew.

"Of course it is difficult because we haven't had so much time to set up the bike, but today was the most difficult moment for him, getting back on the bike. Now he will go improving bit by bit,'' his Fiat Yamaha team manager Daniele Romagnoli said.

Honda Repsol's Dani Pedrosa, who shares the championship lead with Spanish compatriot Lorenzo, will start from fifth, with veteran Suzuki rider Loris Capirossi completing the second row.

LCR Honda’s Randy de Puniet suffered a late crash in an incident-filled session, with Andrea Dovizioso, Nicky Hayden, Shinya Nakano and John Hopkins also having falls.

Alvaro Bautista claimed pole for the 250cc race, with the Spanish Aprilia rider edging out compatriot Hector Barbera and championship leader Mika Kallio.

In the 125cc class, Briton Bradley Smith put his Aprilia on pole, with championship leader Simone Corsi only 11th quickest.