Jorge Lorenzo made a commanding start to the Brno MotoGP weekend as he went quickest in opening practice.
The world champion has not won a race since Mugello in June, the last event prior to his run of injuries, but was a clear step ahead of his rivals on Friday morning in the Czech Republic.
Lorenzo had a few challenges from Yamaha team-mate Valentino Rossi and Honda's Dani Pedrosa, before ending the session 0.343 seconds clear of the latter with a 1m56.698s lap on the checkered flag. Cal Crutchlow was third on the Tech 3 Yamaha, just 0.017sec behind Pedrosa.
Championship leader Marc Marquez, winner of the last three races, was a relatively quiet fourth, 0.422s off the pace. Rossi was pushed down to fifth in the end.
Satellite Honda riders Alvaro Bautista and Stefan Bradl took sixth and seventh, ahead of top Ducati runner Andrea Dovizioso.
Aleix Espargaro set the CRT pace, just 0.086s ahead of Hiroshi Aoyama.
Gresini's CRT rider Bryan Staring was the only man to crash, having a minor fall.