The lovely weather was generous with the premier class and allowed them a fully dry playground for the first practice session, although clouds were starting to gather as the action hotted up. The morning started with Johann Zarco in charge of proceedings but while the grid was struggling to follow the early leader’s suit into the 1:46s, Marc Marquez promptly did eight tenths of a second better and raised the bar for the opposition. It took some time to reel in the championship leader, a task aided by a few moments aboard the Honda, but the familiar presence of Andrea Dovizioso made itself felt for the final third of the session. The Italian got within nine thousandths of a second of the lead but that only spurred Marquez on to extend his lead further. The next challenge from the Ducati came in the final five minutes on brand new rubber, when Dovizioso dipped into the 1:45s and then went on to take a big bite into it. Challengers were plenty but the Ducati safely took the headline ahead of Honda, this time the one of Cal Crutchlow.
Zarco was lead Yamaha after shining throughout the session and stealing the spotlight off his factory teammates to finish third. Unusually for an FP1 session, Marquez also swapped to new tyres – probably persuaded by the changeable weather around these parts – but a few traffic niggles settled him into fourth place, a tenth and a half down on his arch rival. Maverick Viñales had another encouraging showing for Yamaha in fifth, a tenth off the world championship leader and the final rider into the 1:45s.
Behind the headline stealing battle, Andrea Iannone showed the way for Suzuki in sixth position but over half a second in arrears of Dovizioso, while Alvaro Bautista and Jack Miller also had a productive day at the office inside the top eight. Valentino Rossi was a bit slower to get out of bed and looked uncertain on a top ten position until the final couple of minutes bumped him up to ninth. Aleix Espargaro had a similar fate, sneaking into the top ten despite being over a second slower than the leader and to the detriment of Dani Pedrosa, who will have to hope for good weather to ensure a top ten position ahead of qualifying. However, the small Spaniard was not as unlucky as compatriot Jorge Lorenzo, who was back in action for one testing lap but then ruled himself out from the rest of the weekend due to the still painful consequences of his last couple of eventful races.