Lewis Hamilton and Jenson Button face the prospect of being at opposite ends of the grid for Sunday's Australian Grand Prix given the differing fortunes of the two British Formula One stars at the start of the new season.

Melbourne's Albert Park was the scene of arguably one of the most unusual opening days in the sport's history, in particular with a considerable amount of focus on a Sauber team mired in an ongoing legal battle with last year's reserve driver Giedo van der Garde.

The situation at one stage resulted in bailiffs from the Supreme Court of Victoria being on stand-by outside the circuit ready to impound Sauber's cars and trackside equipment in case the team were found to be in contempt.

Then there was Manor, who have moved heaven and earth to make it to Australia after emerging from administration three weeks ago, but due to technical issues neither young Briton Will Stevens nor Spanish team-mate Roberto Merhi made it out of the garage.

At the head of affairs, and unsurprisingly so, were Mercedes duo Nico Rosberg and reigning champion Hamilton, separated by exactly a tenth of a second come the end of the two 90-minute sessions.

As first days go, Hamilton was happy enough but knows there is more to come from a car that looks set to dominate the campaign again.

Hamilton said: "We have a great car, great speed, but still the car is not perfect, so that is something we need to work on.

"It's obviously going to be very close (between himself and Rosberg), and I still have a lot of work to do with balance.

"I'm also not 100 per cent comfy with the car, but that's to be expected because it's the first day."

Rosberg, who topped both sessions with the duo split by just 0.029secs at the end of FP1, knows he cannot give Hamilton an inch if he is to start the season with a victory.

"With Lewis it's always nip and tuck, always quite close, so I need to nail it on Saturday and Sunday," said Rosberg.

"For now I haven't found the car balance 100 per cent. The long run was okay, but for the short run there was too much oversteer.

"That is when the back of the car steps out all the time and it's very risky to drive, but it has still been a good day for us and a good start, so we are very confident for tomorrow."

As for Mercedes' rivals, Ferrari new boy in four-times champion Sebastian Vettel and team-mate Kimi Raikkonen were the best of the rest, with the German 0.7secs adrift.

As for Button, it is abundantly clear the remainder of the weekend - and likely the first few races, potentially the season - are going to be an uphill struggle.

McLaren's new power-unit supplier Honda are continuing to encounter a range of issues, with Button conceding that when it comes to pace and reliability the team "need a bucket load of both right now".

Button finished second practice a staggering 3.7secs adrift of Rosberg and staring at the possibility of being on the back row of the grid should Manor fail to take part in qualifying.

"I'm hoping it won't be the last row - hopefully 20 cars will run!" said Button.

"It's not going to be easy, we all know that. That's the important thing, we are all working as one.

"We are not pointing any fingers, we are just solving the problems as we go and hopefully we will be competitive sooner rather than later.

"There is a lot of hard work needed, but we knew that coming into this season."

As for the time chasm to Mercedes, Button added: "That's what it is. It's big!"

McLaren's day was not helped by Kevin Magnussen - standing in for Alonso this weekend - making a mistake in FP2 that resulted in him running into a wall and breaking the front-left suspension.