Nico Rosberg edges out Lewis Hamilton as Mercedes dominate practice sessions ahead of season-opening Australian Grand Prix

Mercedes dominated free practice at the season-opening Australian Grand Prix on Friday, with Nico Rosberg edging his Formula One world champion team-mate Lewis Hamilton to top the timesheets in both sessions.

German Rosberg, last year's championship runner-up, set the fastest lap of one minute, 27.697 seconds in the second session on a glorious day at Albert Park, topping Hamilton by one-tenth of a second.

Rosberg was also quickest in the first session, his best time of one minute, 29.557 seconds edging Hamilton as the constructors' champions carried their ominous form from winter testing onto the track.

Four-times world champion Sebastian Vettel was third fastest on his debut for Ferrari in the second session, with team mate Kimi Raikkonen fourth best.

But with Vettel's fastest time over seven-tenths of a second adrift of Rosberg, the opening day's practice will strengthen belief that the first rounds of Formula One may be Mercedes versus the rest.

Williams driver Valtteri Bottas posted the fifth fastest lap, with Red Bull's new recruit Daniil Kvyat sixth in the second session.

Kvyat's team mate Daniel Ricciardo had a less memorable day.

Tenth fastest in the first session, Ricciardo was forced to sit out the second after an engine problem, a fate also shared by Williams driver Felipe Massa.

Toro Rosso's 17-year-old driver Max Verstappen impressed with the sixth fastest time of the first session, before falling back to 14th quickest in the second.

Dogged by reliability problems during winter testing, the gloom in the McLaren garage followed drivers Jenson Button and Kevin Magnussen onto the track.

Magnussen, who has taken injured Fernando Alonso's seat at Albert Park, skidded into the gravel at turn six in the second session and his car had to be winched off the track.

That was after he and Button finished slowest of the 15 cars in the first session that posted flying laps. Button improved in the second but only marginally to be 13th fastest.

Having lost a legal challenge from dumped driver Giedo van der Garde, Sauber's troubled leadup continued.

An Australian court found in favour of Van der Garde's bid to force Sauber to let him drive for them and the Dutchman's lawyers filed a contempt of court action against the Swiss team.

Van der Garde was at Albert Park, suited up and apparently ready to drive, but neither he nor nominated drivers Marcus Ericsson and Felipe Nasr drove in the first session.

Swede Ericsson and Brazilian Nasr drove out for the second session but Ericsson crawled back to pit with smoke billowing from the rear of his car midway through.

Manor Marussia, having only recently emerged from administration, were unable to put either of their cars on the track in the first session.