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Nico Rosberg has kicked off the 2015 Austrian Grand Prix with the fastest time in first free practice around the Red Bull Ring, but problems for Ferrari's Sebastian Vettel would see him miss much of the session, while the embattled Fernando Alonso would also strike yet more issues in the McLaren.
Fastest throughout almost the entire session, Rosberg's benchmark lap of 1min 10.401secs was clocked early on and was good enough to retain a plus-second lead over Lewis Hamilton for some time until the championship leader eventually reduced it to three tenths.
The Briton might have stood to go quicker but for a wild moment at turn eight on one of his quicker laps, the defending champion one of many drivers to venture across the run-off zones during the session as the drivers found the limit of the evolving circuit, particularly at turn one.
Behind the two Mercedes', Kimi Raikkonen led the chase for Ferrari six tenths behind in third, but there are furrowed brows in the adjoining garage after Vettel's car came to a halt early on having lost drive in fourth gear, the German sitting out the remainder of the session to prop up the timesheets.
Having started on the front row in 2014, Valtteri Bottas got Williams' weekend off to a positive start in fourth position, ahead of Felipe Nasr, the Brazilian lifting his Sauber up into the top five unexpectedly with a late flyer.
Daniil Kvyat and Daniel Ricciardo followed up in sixth and seventh, though they head into the weekend knowing they will both need to take a penalty hit for an engine change after qualifying.
Despite a few off-track moments, Max Verstappen was still good enough for eighth quickest, ahead of Felipe Massa, who was inadvertently involved in a heart-stopping moment with Maurizio Arrivabene when the Ferrari team principal stepped off the pit wall into the path of the Williams driver as he was pulling away. Some quick reflexes by both prevented a more serious incident.
Sergio Perez rounded out the top ten for Force India, ahead of Carlos Sainz and leading Lotus driver Pastor Maldonado, with his 'temporary' FP1 team-mate Jolyon Palmer less than a tenth behind in 14th before he hands the E23 back to Romain Grosjean.
Elsewhere, McLaren-Honda's weekend got off to another poor start as Fernando Alonso spent much of the session inside the garage having developed yet more mechanical issues, and though 17th place Jenson Button managed 30 laps without incident, he was a full eight tenths shy of Marcus Ericsson ahead in 16th.