Andrea Dovizioso set the initial pace before Hector Barbera set the fastest time of the day on a drying track in the second practice session at the German MotoGP on Friday.
Championship leader Dovizioso (Ducati) led the way in the opening session with a fastest lap of one minute 21.599 seconds, with his nearest rival in the battle for the title, Maverick Vinales, second-quickest just 0.038 secs slower.
Dani Pedrosa was third in FP1, while Valentino Rossi was left pushing his Movistar Yamaha bike after enduring technical issues.
Reale Avintia Racing rider Barbera was the quickest in FP2 ahead of Repsol Honda duo Marc Marquez and Pedrosa.
Barbera's lap of one minute 28.115 seconds put him top of the timesheets, bettering fastest Marquez's circuit by 0.063 secs on a surface which was drying out following a combination of sunshine and heavy showers.
A shower prior to the start of the second session ensured the riders went out on wet tyres, but they were switched to dry when conditions eased before the rain came again.
Italian Rossi, a winner in Assen last weekend, was only 15th in FP2 and Vinales was down in 20th spot on a day in which both sessions were extended by 10 minutes to enable the riders to get used to a new surface.
Andrea Iannone (Team Suzuki Ecstar), Scott Redding (Octo Pramac Racing) and Alvaro Bautista (Pull&Bear Aspar Team) all suffered crashes in FP1.