Lewis Hamilton is on track to start the new Formula One season on a winning note - but not after taking an embarrassing backward step.

Less than five minutes after the sport's new era began in earnest at Melbourne's Albert Park with first practice for the Australian Grand Prix, Hamilton ground to a halt in his Mercedes on its installation lap.

Prior to the session, Hamilton's team of mechanics were forced into a change of the new 1.6-litre V6 turbo-charged power unit.

Once on track, and after just half a lap, a sensor calibration issue resulted in the power unit cutting out, bringing Hamilton's running to an abrupt end.

There was a further red-faced moment, albeit in a comedic way, when a security guard tried to stop Hamilton from re-entering the paddock on his return as he was not wearing the required pass, even though he was still in his race overalls and wearing his helmet.

Come the second session, Hamilton made up for lost time by completing 37 laps - only three other drivers managed more - whilst setting the best time of one minute 29.625secs.

At the end of what he described as "a day of two halves", that was enough to put a smile on his face as he said: "To miss the first session was unusual. I didn't even get round half a lap when I had to stop and I felt then I was on the backfoot.

"It was a big back step before we had even got going, so heading into P2 I felt really uncomfortable because I hadn't done any laps.

"As I hadn't driven for a couple of weeks (since the final day of testing) I felt raw, like a complete beginner.

"But I got up to speed quite quickly and I found a balance relatively fast, so I feel positive and quite comfortable in the car now."

Unsurprisingly, given little can often be read into Friday practice times, Hamilton was dismissive of his front-running pace.

"It doesn't make any difference whether you're top of the timesheet or not. It's all about qualifying and the race," remarked the pre-season championship favourite.

"I've still a lot to improve on, a lot to find, but we have a nice foundation after what happened in P2.

"Hopefully I can build on that into P3 (on Saturday) and we'll see where we end up in qualifying."

Mercedes, though, appear strong because Hamilton and team-mate Nico Rosberg were a second quicker than any of their rivals on long-run pace.

Over one lap, Rosberg finished 0.157secs adrift of Hamilton, with the duo comfortably ahead of Ferrari's Fernando Alonso, Sebastian Vettel in his Red Bull and McLaren's Jenson Button.

Vettel completed a session-high 40 laps, a veritable triumph given Red Bull were one of the teams worst affected by pre-season gremlins.

The reigning four-times champion even sat out the opening 50 minutes of FP1 as his crews changed the floor on his troublesome car.

But with new team-mate Daniel Ricciardo sixth fastest, there appears to be light at the end of the tunnel for Red Bull.

Vettel said: "In a way it's a relief, the fact that we were running, we didn't have any problems, the balance was good and the performance looked all right.

"In the end Friday times are not worth a lot, but it's better to be close to the top rather than somewhere towards the back, so I'm very happy with that.

"We will do what we can to prepare for Saturday and Sunday, but let's see where we are then - the most important thing is we finish."

Surprisingly, Williams pairing Valtteri Bottas and Felipe Massa were eighth and 12th respectively, despite their pre-season standing as second favourites behind Mercedes for the constructors' crown.

Although the sessions were not as chaos strewn as perhaps had been anticipated, there are two teams in serious trouble - Caterham and Lotus.

The two Renault customers managed a combined total of just 17 laps across the four cars due to a range of problems for Caterham duo Kamui Kobayashi and rookie Marcus Ericsson and Lotus pair Romain Grosjean and Pastor Maldonado.