Marquez remains fastest despite Yamaha challenge

Marc Marquez was fastest in the first free practice for the Aragon Grand Prix. (Photo: AFP/Jose Jordan)

Maverick Vinales, Valentino Rossi and Fabio Quartararo were the fastest in the afternoon but none of the trio were able to approach Marquez's earlier time of 1min 46.689sec.

"Today we started very well and actually we ended quite well too," said Marquez.

Vinales set the best afternoon time in 1:48.014, 0.057sec ahead of factory Yamaha teammate Valentino Rossi, with Quartararo, who rides for a Yamaha satellite team, 0.103sec slower.

If the forecast rain arrives on Saturday morning for the third practice session, it could make it more difficult for the others to stop five-time top-class world champion Marquez taking pole position.

Apart from Marquez, who escaped a crash unscathed, all the other riders improved their times in the afternoon, with fellow Spaniard Pol Espargaro putting his KTM in fifth.

"In the afternoon we worked a lot with used tyres and unfortunately had a small crash but we learned a lot from it," added Honda rider Marquez.

"Aside from this little fall everything went well and I think there's still some more time to find."

Marquez leads Andrea Dovizioso of Ducati by 93 points in the riders' standings with six races left to run. The Italian only had the eighth-best combined time in the first two practice sessions.

The riders with the ten fastest times in the first three free practice sessions participate directly in Saturday's qualifying session (Q2), which determines the order of the top 12 places on the starting grid for the race on Sunday at 13:00 local time (1100 GMT).

The other drivers must participate in a preliminary qualifying session (Q1) and the best two times are drafted for Q2.

"The weather forecast for tomorrow isn't fantastic, so everybody tried really hard to stay inside the top 10 today because FP3 might be wet," said nine-time world champion Rossi.

"Usually when we make improvements in the dry it's the same in the wet. Maybe we have a chance tomorrow to try and understand if we're stronger in the wet conditions."