FP1 saw a complete turnaround for Maverick Viñales. After finishing dead last in the Sachsenring, the Monster Energy Yamaha rider set the fastest time of the first session of practice in Assen. It was not all sweetness and light, however, Viñales nearly losing the front of his Yamaha M1 at Madijk and shaking his head and fist vigorously.
Viñales wasn't the only surprise at the top of the timesheets in FP1. Repsol Honda rider Pol Espargaro was also quick, crossing the line in second, a tenth behind the Yamaha. Viñales and Espargaro had a comfortable lead over Alex Rins, the Suzuki rider three tenths off the time of Espargaro.
Championship leader Fabio Quartararo ended the session in fourth, just ahead of Johann Zarco, who saved a preliminary spot in Q2 with a late lap to jump from seventeenth to fifth. Danilo Petrucci had something of a resurgence on the Tech3 KTM, ending as sixth fastest, ahead of Aleix Espargaro on the Aprilia, Takaaki Nakagami on the LCR Honda, and the winner at the Sachsenring, Marc Marquez, in ninth. Marquez was riding a brand new chassis for the first time in FP1. Aprilia's second rider, Lorenzo Savadori, rounded out the top ten, a strong showing by the Italian.