Andrea Dovizioso came out the blocks quickly to lead first practice for the Austrian Grand Prix at the Red Bull Ring, stealing the top spot from Marc Marquez late on.
The Ducati man spent most of the session evaluating different race settings, but spent most of the session in the top five before his final flyer.
Marc Marquez had looked to secure the quickest time of the session for the majority of the 45-minutes, having picked up where he left off from Brno.
The Honda rider posted a 1:24.338 early in the session to lead the Yamaha of Maverick Vinales, shortly before running off into the gravel at Turn 4 while trying to move ahead of the M1.
He tried to dive up the inside of Vinales in an attempt to find some clear track space, but braked too late and ran straight on into the gravel trap on the exit of the corner. The championship leader stayed on his RC213-V and rejoined the circuit shortly after.
Marquez then shaved just over a tenth from his benchmark with a 1:24.218, before Dovizioso pipped the Spaniard in the dying seconds with a pair of new soft compound tyres with a 1:24.033 to bring FP1 to a close as leader.
Vinales ended the session third fastest ahead of the second Desmosedici GP19 machine of Jack Miller-the satellite Pramac rider well clear of factory man Danilo Petrucci who could manage just the 14th quickest time.
Valentino Rossi rounded out the top five in what was a promising session for Yamaha, as Petronas SRT rookie followed just behind in sixth.
Alex Rins flew Suzuki’s flag on the sole GSX-RR competing this weekend following the news that Joan Mir would miss the Austrian round after a violent crash during the post-race test at Brno on Monday.
Johann Zarco meanwhile posted an impressive eighth fastest lap to start the KTM factory squad's home race weekend in a positive fashion, while Tech 3 KTM’s Miguel Oliveria also showed well to close out the top ten runners just behind LCR Honda’s Takaaki Nakagami.
Hafizh Syaharin may be in doubt for FP2 after he crashed heavily at Turn 9 in the final minutes of the session, the Malaysian being caught out by a high-side as he turned in to the high-speed turn.
His RC16 collected the air fence while he hit the ground hard, needing trackside medical assistance shortly afterwards.