Championship leader Fabio Quartararo topped the San Marino MotoGP opening practice times dominated by Yamaha at Misano on Friday.
Quartararo posted a quickest lap of 1min 32.189sec on the Yamaha satellite SRT bike, edging Maverick Vinales on a Yamaha factory bike, with the French rider's SRT teammate Franco Morbidelli taking third.
Then came in a pair of KTMs ahead of another Yamaha, with Valentino Rossi on board.
Quartararo, who won the first two races, holds a slender three-point lead in the standings going into this sixth leg of the coronavirus-disrupted season.
In second place in the hunt for the 2020 MotoGP crown is Andrea Dovizioso who could only muster the 11th quickest time over the combined sessions on his Ducati.
Six-time champion Marc Marquez remains sidelined as he recovers from a broken arm suffered in the opening race.
San Marino MotoGP combined first and second free practice times
1. Fabio Quartararo (FRA/Yamaha): 1:32.189,
2. Maverick Vinales (ESP/Yamaha) at 0.009s,
3. Franco Morbidelli (ITA/Yamaha-SRT) 0.178,
4. Pol Espargaro (ESP/KTM) 0.287, 5. Iker Lecuona (ESP/KTM-Tech3) 0.486,
6. Valentino Rossi (ITA/Yamaha) 0.543,
7. Danilo Petrucci (ITA/Ducati) 0.636,
8. Brad Binder (AFS/KTM) 0.731,
9. Miguel Oliveira (POR/KTM-Tech3) 0.746,
10. Aleix Espargaro (ESP/Aprilia) 0.74