SPIELBERG, Austria, June 26 (Reuters) - Formula One championship leader Kimi Antonelli was fastest in first practice for the Austrian Grand Prix on Friday, with Mercedes teammate George Russell a close second (+0.040) as rivals suffered reliability issues.
McLaren's Oscar Piastri set the third-quickest time, 0.117 slower than 19-year-old Italian Antonelli, ahead of Red Bull's Max Verstappen (+0.281) and Ferrari's Lewis Hamilton (+0.665).
Racing Bulls' rookie Arvid Lindblad was sixth, with McLaren's Lando Norris seventh.
Seven-time world champion Hamilton won the previous round at the Circuit de Barcelona-Catalunya for his first victory since joining Ferrari from Mercedes last year. He goes into the weekend 41 points behind Antonelli, who has won five of seven races.
Red Bull, at their home circuit, had a difficult start with Verstappen suffering issues with his upgraded car while teammate Isack Hadjar's car needed a hurried engine change and he missed the first 35 minutes.
Four-time world champion Verstappen complained that "the whole car is shaking under braking".
"At first we had an engine issue on Isack's car before the beginning of the session, so we had to do a very late call to change his engine," said team boss Laurent Mekies.
"And then on Max, we also had a troubled start with a couple of software issues that got us stuck in the garage."
McLaren also had reigning world champion Norris in the garage for the first 45 minutes as they wrestled with a hydraulics problem while Piastri complained about his car's brakes.
Ferrari had F2 driver Dino Beganovic in Charles Leclerc's car for the session, clocking the ninth best time, with the Monegasque returning for the later hour.
Sergio Perez's Cadillac brought out red flags with just over a minute remaining after the Mexican stopped on the uphill climb, with the session then ended prematurely and no drivers able to do any practice starts.
Japanese driver Ryo Hirakawa replaced Esteban Ocon at Haas for the session and knocked over one of the team mechanics when he overshot his pit box, fortunately without injury.
(Reporting by Alan Baldwin; Editing by Hugh Lawson)
