Assen MotoGP: Rossi leads opening practice as Marquez crashes

Rossi, using a new Yamaha frame this weekend, posted a best time of 1:34.357 to lead from Honda rival Marquez, nearly two tenths of a second off the Italian's pace.

Marquez, using the 2014 Honda chassis, finished in front of teammate Dani Pedrosa and Yamaha's Jorge Lorenzo. Unlike their teammates, both men were using their regular chassis.

Pol Espargaro completed the top five on the Tech 3 Yamaha.

The session had a disastrous start for Marquez, who lost control of his bike on his out-lap and ended up crashing after running through the gravel.

Marquez managed to get his bike going again and returned to the pits, his bike appearing not to suffer significant damage.

The Spaniard returned to the track some 10 minutes later, but only managed the ninth fastest time in his first run.

Teammate Pedrosa showed strong pace right from the beginning, leading the times with a 1:34.823 lap 10 minutes into the session.

Lorenzo joined his compatriot in the 1:34s a few moments later, but nearly three tenths behind.

Marquez managed to improve to seventh place as the session progressed, but the Spaniard continued to be quite some way off Pedrosa's pace.

Rossi jumped to second place with some 16 minutes left with a lap just 0.017s seconds slower than Pedrosa's.

Marquez went third quickest 10 minutes later, but not before going off track during his run. He improved his time, but not his position, on the following lap, joining the top two in the 1:34s.

The world champion then took P1 on the third flyer of his run with a 1:34.552. He was relegated seconds later, however, when Rossi completed a lap +0.073s quicker than the Honda rider.

The Italian went even quicker with a minute of the session remaining to end the morning on top by 0.195s.