Not even a crash and switch to his spare bike could prevent Casey Stoner taking his ninth pole position of the 2011 MotoGP season at Aragon on Saturday.

The world championship leader had just pushed pole almost a second ahead of Repsol Honda team-mate and nearest rival Dani Pedrosa - despite a 'cautious' first lap on the softer rear tyre - when he then ran off track and was forced to ditch his RC212V.

"It was a very eventful qualifying session for us!" said Stoner. "At the end of the session we put on the soft tyre and on the first lap I was a little too cautious in T1 as I wasn't sure if the tyres were warm enough.

"Then I pushed on the second lap and I had a lot more grip than I expected so I went through the corner much faster and I wasn't able to slow down. I pulled the bike up but it was difficult to reduce the speed and I ended up needing to lay the bike down to avoid the wall."

After switching to his less favoured spare bike, Stoner returned to the track and went even faster, claiming pole by 0.296sec from Pedrosa and 0.704sec from Ben Spies (Yamaha).

"Unfortunately, I wasn't able to restart the [crashed] bike which is a shame as I was happier on that one, but even on the second bike we were able to improve our time," he said. "Now we need to see what the weather brings for tomorrow but we're feeling good and I hope for a good race".

Stoner will start the race 35 points clear of Spies' team-mate Jorge Lorenzo, who qualified fourth on the grid, 0.819sec down on Stoner.

Pedrosa meanwhile is looking for further set-up improvements in order to stay with Stoner on Sunday.

"I'm happy with the first row on the grid. I've pushed to the limit to get a good position and we achieved it, but to be honest we still need to tune the set up of the bike a little, especially in front because I don't feel as comfortable as I'd like to and I'm struggling a little under braking," said the home star.

"For the race pace, Casey is quicker than us, he is riding very fast and smooth, so I guess he will set the pace tomorrow and we will need to stay close from the beginning of the race. Let's hope we can find something else on the setting tonight and have a good race in front of the Spanish fans".

Pedrosa will start round 14 (of 18) 35 points behind team-mate Andrea Dovizioso, who is third in the championship. Dovi will start fifth.

"I'm quite satisfied with this qualifying session as we have a good race pace but Casey is so strong and seems unbeatable," he admitted. "We will do our best to strengthen our position in the Championship and we want to fight Dani's comeback and gain some points on Lorenzo."

The Repsol Honda bikes and riders will have a special livery created by Spanish designer David Delfi for race day at Aragon.