Hamilton broke his wishbone, which caused his spin
Hamilton, who ultimately qualified fourth fastest, lost control of his car on the exit of the Turn 12/13 chicane as he pushed to improve his grid position, with the Briton claiming that something had broken on his car when speaking to the media after the session.
Following post-qualifying checks, Mercedes team boss Ross Brawn said a wishbone issue was uncovered, but has no doubts that both cars will be safe to race tomorrow.
"When we got the car back, we had fractured a wishbone. That's why he lost control of the car," said Brawn. "It's a circuit where there is a lot of grief over the curbs and so on and we're going back through the data to understand what may have provoked it.
"It's a system we have had for a long time with no problem so it may be an issue with that particular part or it may be an issue with the way we are taking some curbs. I don't think there is any high risk for tomorrow and we should be able to fix it in parc ferme."
Nico Rosberg qualified in third position to make it an all-Mercedes second row.