Edwards fastest in first practice

Edwards upstaged his Fiat Yamaha teammate Valentino Rossi, who ended the session down in 17th, to complete two quick laps right at the end of the session.

After moving to the top of the times shortly before the chequered flag, he then bettered that effort on his final tour to end the session almost four tenths of a second clear of Chris Vermeulen on the Rizla Suzuki.

Vermeulen also saved his best until the end, completing his two fastest laps right at the end of the session to just outpace his teammate John Hopkins. Repsol Honda's Dani Pedrosa was fourth fastest overall, after also setting his best lap late on.

Practice had started off fairly quiet, with Ducati Marlboro's Casey Stoner being the first of the title contenders to show his hand, moving to the top of the timesheets at the halfway stage of the one-hour session.

Before that Pramac D'Antin's Alex Hofmann and Dunlop Yamaha Tech 3's Sylvain Guintoli had enjoyed their moment in the limelight after sharing the top spot during the early part of practice.

Stoner went quicker again shortly afterwards before Alex Barros on the Pramac D'Antin Ducati then moved to the top of the timesheets with 15 minutes to go.

By this stage of the session all of the front-runners began finding the limits of their bikes and with 12 minutes to go Marco Melandri went quickest, before Hopkins moved to the top of the timesheets with just five minutes remaining.

Hopkins had looked set to keep that spot until the late efforts from Edwards and Vermeulen pushed him back to third.

Hofmann maintained his strong form through the hour, ending practice fifth overall, ahead of Melandri - who came off his bike without injury at Turn 1 - and Kawasaki's Olivier Jacque.

Ducati Marlboro's Loris Capirossi appeared much happier with his bike to end up eighth overall, ahead of Shinya Nakano and Guintoli.

World champion Nicky Hayden was 11th, with Stoner eventually dropping back to 13th overall after a minor fall later in the session.

However, the fears of his rivals about the topline speed of his Ducati appeared well justified with Stoner quickest overall through the speed trap once again.

Practice one times:

Pos  Rider             Bike      Time
 1.  Colin Edwards     Yamaha    1:57.422
 2.  Chris Vermeulen   Suzuki    1:57.794
 3.  John Hopkins      Suzuki    1:58.554
 4.  Dani Pedrosa      Honda     1:58.597
 5.  Alex Hofmann      Ducati    1:58.800
 6.  Marco Melandri    Honda     1:58.802
 7.  Olivier Jacque    Kawasaki  1:58.821
 8.  Loris Capirossi   Ducati    1:58.857
 9.  Shinya Nakano     Honda     1:59.016
10.  Sylvain Guintoli  Yamaha    1:59.078
11.  Nicky Hayden      Honda     1:59.209
12.  Alex Barros       Ducati    1:59.371
13.  Casey Stoner      Ducati    1:59.426
14.  Carlos Checa      Honda     1:59.921
15.  Toni Elias        Honda     2:00.362
16.  Makoto Tamada     Yamaha    2:00.417
17.  Valentino Rossi   Yamaha    2:00.539
18.  Randy de Puniet   Kawasaki  2:00.941
19.  Kenny Roberts Jr  KR        2:03.333