Spielberg bei Knittelfeld - Andrea Dovizioso made the most of dry morning conditions as Ducatis dominated the free practice sessions on Friday ahead of the Austrian MotoGP.
With rain forecast for the afternoon, the morning brought a series of aggressive rides as Ducati, which grabbed the top two places in the previous race in Brno, continued to take the attack to championship leader Marc Marquez (Honda).
Italian Dovizioso was fastest in the morning, followed by factory Ducati team-mate Jorge Lorenzo and Italian Danilo Petrucci on a Pramac Ducati with Spaniard Marquez fourth.
After the start of the afternoon session was held up by a rain storm, Marquez was fastest in the wet, but more than 10 seconds slower than the best time in the morning.
In the dry, Dovizioso, winner in Austria last year and in Brno last week, completed his best lap in 1min 23.83sec, 0.215 ahead of Lorenzo. Marquez was fourth more than half a second slowed at 1:24.411.
In the rain, Marquez recorded the best time of 1min 33.995 sec. Scott Redding (Aprilia) was second fastest followed by the two factory Ducatis with Lorenzo this time ahead of Dovizioso.
"Wet but nice first day," Lorenzo tweeted.
Italian Franco Morbidelli (Honda Marc VDS) who had the 17th best time of the day will be relegated three places on the starting grid for "irresponsible" riding after slowing and blocking another bike.
Some showers are forecast for Saturday when a final free practice session is scheduled for the morning before qualifying in the afternoon. The track should be dry for Sunday's race.
Free practice times after two sessions:
1. Andrea Dovizioso (ITA/Ducati) 1:23.830, 2. Jorge Lorenzo (ESP/Ducati) at 0.215, 3. Danilo Petrucci (ITA/Ducati Pramac) 0.490, 4. Marc Marquez (ESP/Honda) 0.581. 5. Andrea Iannone (ITA/Suzuki) 0.606, 6. Dani Pedrosa (ESP/Honda) 0.644, 7. Cal Crutchlow (GBR/LCR Honda) 0.661, 8. Tito Rabat (ESP/Ducati Avintia) 0.846, 9. Johann Zarco (FRA/Yamaha Tech3) 0.937, 10. Maverick Vinales (ESP/Yamaha) 1.005
Selected: 11. Valentino Rossi (ITA/Yamaha) 1.054