Jorge Lorenzo was quickest in practice for the final MotoGP race of the season and Marc Marquez suffered a minor crash ahead of Sunday's title decider in Valencia.

Ducati rider Lorenzo clocked one minute, 30.640 seconds in the second session in his homeland at Circuit Ricardo Tormo on Friday after Andrea Iannone was fastest in FP1.

Marquez, who holds a 21-point lead over Andrea Dovizioso, was fifth in an FP1 which the Italian finished in fourth spot as he attempts to pull off an unlikely late raid for what would be his maiden premier class title.

Three-time champion Marquez ended the day with a crash, but was unharmed as he could only set the fifth-fastest time in the second session, with Dovizioso third behind Dani Pedrosa and Lorenzo. 

Dovizioso kept his slim title hopes alive with a win in Malaysia last time out and needs another victory along with a spectacular failure from Repsol Honda's Marquez on home soil to be crowned champion.

Marquez walked away without doing damage after losing control at turn two in an unconvincing start to his bid to seal a fourth MotoGP title.

Johann Zarco set the fourth-fastest time of the day in FP2, while Valentino Rossi and Movistar Yamaha team-mate Maverick Vinales were down in 11th and 12th respectively.

Jack Miller and Pol Espargaro filled the top three in the first session, the Australian also taking a tumble.