Dani Pedrosa admitted that his early crash in Aragon qualifying disrupted his pole bid.
The Honda rider was mystified by the fall on his first run, which forced him onto his spare bike for the rest of the session.
"I was on a slow lap, I don't know what happened there," said Pedrosa.
"I lost the front when I was completely straight.
"So I lost a lot of time. I had to go back to the pits and change my leathers.
"When I took the second bike it was hard because I knew it was the only bike remaining for me.
"I had to settle for a while and do a lap just to make sure I was at the front of the grid."
Pedrosa ultimately qualified second, between the Yamahas of Jorge Lorenzo and Cal Crutchlow.
"Towards the end I could forget about it all and push harder," said Pedrosa.
"The front row is always good and we hope to do a good start and a good race."
- Dani Pedrosa