Australian GP: Nico Rosberg hopes Ferrari can catch Mercedes in F1

Hamilton and Rosberg finished half a minute clear of the pack in Melbourne, but Ferrari newcomer Vettel defeated Felipe Massa's Williams to secure the remaining podium spot.

"For the next couple of races, we will be leading the way and we will try and keep it that way," said Rosberg.

"But it would be good if they can come a bit closer, so long as they don't come too close," said Rosberg of Ferrari.

Asked by Vettel if he was "being serious?" Rosberg said it would be better for F1 if Ferrari was able to pressure Mercedes.

"I hope you can give us a challenge because it's important for the sport and the fans," he replied to Vettel.

"A part of me thinks about the show because I want to give people a great time at home.

"If you do come a bit closer, that would be awesome."

Hamilton also expects Ferrari to be a bigger factor as 2015 goes on.

"Sebastian must have done a good job to get to where he is today," said the race winner.

"I have not seen the times but I think the Ferraris have taken a huge step forward.

"Clearly they have made one of the biggest steps, so we cannot back off.

"I anticipate we might have a good fight with them at some stage this year."

MERCEDES BATTLE UNDER CONTROL

Hamilton led throughout the race, and although the gap fluctuated between one and four seconds as Rosberg saved fuel at times and pushed at others, the champion said it was always in hand.

"Nico was very quick throughout the race," he said. "Once you get a two-second gap you try to manage that.

"There's no need to eke out more, but when Nico turned up the heat, I was able to react, which is good."

Rosberg admitted that Hamilton had matched every tactic he tried.

"The attack was most definitely there," he said. "But Lewis made no mistakes, it was not possible to get closer than that, let alone try to overtake.

"It was a matter of saving a little bit of fuel in the middle of the race to be able to go full-on at the end.

"But Lewis did a similar thing, so in the end he could also push, so it didn't really help me unfortunately."