The Spanish rider prevented defending champion Casey Stoner from completing a clean sweep of all three practice sessions by topping the timesheets on his Yamaha in one minute 55.302 seconds.

Stoner (Honda) dropped to third in 1min 55.674secs after dominating the opening sessions as Cal Crutchlow (Tech 3 Yamaha) also went faster than him.

"I am very happy because we improved a lot on yesterday's lap time. I'm also happy for Cal in second, the bike seems much better than last year for us," said Lorenzo.

"I think we have even more potential for improvement. We still have a few issues to solve, especially corner entry, but we managed to keep a good pace."

The Australian, who was quickest in opening practice on the Losail circuit on Thursday, maintained that form in the second session on Friday, going fastest in 1:55.960.

He just managed to edge out Lorenzo by 0.214 with Italy's Andrea Dovizioso (Yamaha Tech 3) third quickest.

Dovizioso continued that form in the final session this evening as he went fourth quickest.

But Ben Spies (Yamaha), who was fourth in second practice, could only manage 11th in the final session after crashing early on.