Jorge Lorenzo topped the timesheets in the opening practice session for the Czech Grand Prix, as second-fastest man Marc Marquez took a trip to the gravel.
Marquez was the pacesetter early on in the 45-minute session, becoming the first rider to break through the 1m57s barrier with a 1m56.898s in the opening laps.
Shortly after coming within 0.021s of his own benchmark, the Repsol Honda rider arrived at Turn 13 - the penultimate corner of the Brno circuit - too hot, running wide into the gravel as a result and dropping the bike close to the barriers.
Marquez was able to make it back to the pits with no obvious signs of damage to the bike, but he was deposed from the top spot shortly after by Ducati's Andrea Dovizioso, who went 0.077s faster.
Lorenzo then lowered the benchmark by a further 0.322s with a new best lap of 1m56.499s, a time that would go unchallenged for the remainder of the session, Marquez coming within 0.151s once he got back on track to retake second.
Marquez's teammate Dani Pedrosa was the biggest mover in the final part of the session, steadily climbing up the order to third with a succession of late hot laps, ending the session 0.285s adrift of Lorenzo.
Dovizioso, helped by a revised engine and fairing for the Ducati, held on to fourth place, ahead of teammate Andrea Iannone, with Valentino Rossi fending off Tech 3 rider Bradley Smith to take sixth, albeit 0.539s off the pace.
Completing the top 10 were the two works Suzukis of Aleix Espargaro and Maverick Vinales and Cal Crutchlow's LCR Honda.
|17||Mike Di Meglio||Ducati||1'58.589||2.090|
|20||Loris Baz||Yamaha Forward||1'58.720||2.221|
|23||Claudio Corti||Yamaha Forward||2'00.074||3.575|
|24||Alex de Angelis||ART/Aprilia||2'00.122||3.623|