It will come as no surprise that Marc Marquez made a solid start on his home playground, the Spaniard leading the way throughout FP1. He initially did so with a half second gap and after rivals steadily reduced that, Marquez put in a brand new soft rear tyre and promptly increased his advantage to over a second. Reigning champion Joan Mir was the only other rider tempted by shiny new rubber in the closing stages of the morning session, but the Suzuki man only reduced the gap to just under one second. Pecco Bagnaia stuck to used tyres for his final run but showed very solid pace on his way to third on the timesheets.
Alex Marquez made a late jump to join his brother in the top 4, with Jack Miller closely behind in fifth. Aleix Espargaro was the lead Aprilia in sixth, while brand new teammate Maverick Viñales finished 19th, two seconds off the lead but bearing in mind that one second of that was the Marquez effect. Johann Zarco ended the morning just ahead of compatriot Fabio Quartararo in seventh and eight places, while Honda completed the top 10 with Takaaki Nakagami and Pol Espargaro. Enea Bastianini missed out on the top 10 by only six hundredths of a second, with Alex Rins down in 14th and Jorge Martin 17th.