Spielberg - Lewis Hamilton topped the times for Mercedes ahead of Ferrari's Sebastian Vettel in Friday's opening free practice at the Austrian Grand Prix.
On a hot day at the Spielberg circuit in the Styrian Alps, the defending five time champion set a best lap time in one minute and 4.838 seconds on soft tyres to finish just 0.144 seconds ahead of four-time champion Vettel, the German setting his lap time on mediums.
Championship leader Hamilton's Mercedes team-mate Valtteri Bottas was third after making a belated entry to the fray following a pre-session engine change after the team found an oil leak.
Charles Leclerc in the second Ferrari was fourth ahead of Max Verstappen and his Red Bull team-mate Pierre Gasly, Carlos Sainz of McLaren and Daniel Ricciardo of Renault.
Kevin Magnussen was ninth for Haas ahead of British rookie Lando Norris in the second McLaren.
The session was run in hot conditions with a shimmering air temperature of 24 degrees and a track temperature of 52.
The action was interrupted in the closing stages when it was red flagged after Nico Hulkenberg ran over a 'sausage' kerb ahead of the main straight and lost a piece of his Renault's front wing.
After the flat open spaces at Le Castellet, which many critics said is more suitable for testing than racing because it has been so heavily sanitised, the swooping Austrian track delivered a very different kind of challenge.
The kerbs, designed to ensure that drivers stay within the confines of the track without running wide to take advantage, damaged many cars, notably their front wings.