Ben Spies saw his Misano MotoGP qualifying hopes take a knock when he clipped a bump and slid off at the turn one chicane, just after the halfway mark of the session.
The Factory Yamaha rider was holding a front row place at the time, but found his second bike less suitable and dropped back to eighth by the conclusion of the hour.
“It was unfortunate this afternoon, we just got off the line a little and hit a bump in turn one,” explained Spies. “That was the bike with the set-up we were comfortable with. I had to go out on the other bike and there was no time to change the set-up.
“We still need to make some changes to the other set up for tomorrow as we know we had some things to work on before the crash. I'm actually confident we can go pretty quick but with the way the weekend has been we haven't had enough dry time yet to finalise a perfect set up.”
Team-mate and title leader Jorge Lorenzo qualified second.