No sooner had Mercedes cruised to the chequered flag at Sunday's season-opening Australian Grand Prix, their rivals were all but conceding the 2015 Formula One championship was as good as over.

Dominant in 2014, Mercedes were again in a class of their own with double world champion Lewis Hamilton coasting to victory over team mate Nico Rosberg.

Despite taking it easy throughout the 58-lap race, concerned more about saving tyres and fuel than checking their mirrors for challengers, Mercedes finished more than half a minute clear of third-placed Sebastian Vettel's Ferrari.

Only two other drivers finished on the same lap as the Silver Arrows.

"You have to be realistic," said Vettel after his first race for Ferrari. "This weekend it was in their hands and they did a great job, not just as a team but individually.

"They are the favourites, they had a huge advantage last year and I think they did a good job increasing that advantage this year."

Vettel won four titles in a row for Red Bull before Mercedes overtook them last year, and that team's principal Christian Horner said 2015 was looking like another procession.

"On today's evidence we're set for a two-horse race at every Grand Prix this year," he said.

"Take nothing away from Mercedes, they've done a super job, they've got a great car, they've got a fantastic engine, and they've got two very good drivers.

"But the problem is the gap is just so big you end up with three-tier racing and I don't think that's healthy for Formula One."

Mercedes won 16 of 19 races last season and started 18 on pole. If Sunday was anything to go by, they may be even more dominant this year.

"I feel a bit for the fans," said Australia's Daniel Ricciardo, who finished sixth for Red Bull. "It was a boring race. It was frustrating."

Even the Mercedes drivers have said they fear their dominance could drive fans away. In the lead-up to the race, Hamilton admitted he would be bored as a fan while Rosberg said he hoped the others could catch up.

"I hope they can give us a challenge, because it's important for the sport and the fans," the German said.

"Half of me, or part of me, thinks about the show because I want to give people a great time at home watching on TV or at the track." – Reuters