Marc Marquez ended the first session of free practice on top of the timesheets, as the MotoGP pack took to the track in dry and relatively cool conditions. With rain threatening for the rest of the weekend, the rack was busy from the off, riders searching for a dry set up.
Suzuki's Maverick Viñales was a constant threat at the top of the timesheets, leading on and off, but the Spaniard would be outdone by Marc Marquez in the final third of the session, the Repsol Honda rider taking a clear lead. Viñales held on to second, just ahead of Pramac Ducati's Scott Redding.
Andrea Iannone was the second Ducati home, the Italian putting in a quick lap fresh from his return from injury, and just pipping Valentino Rossi into fifth. The Movistar Yamaha rider had hovered near the top of the timesheets throughout, but late charges by others knocked him down the order, despite very tight margins in the top eight.
Rossi's teammate Jorge Lorenzo ended the session in tenth spot, safely through to Q2 should it rain for the rest of the weekend. A mistake on his final lap meant no further improvement was possible.