Manama: Mercedes have admitted that their dominance at the summit of Formula One is over, with Ferrari pledging to make further inroads into the world champion's advantage.

Lewis Hamilton has won three of the first four races this season, including here in Bahrain, but Ferrari have shown a remarkable turnaround from their worst season for more than two decades.

"Looking at the result, we were not dominant and Ferrari are catching up," Toto Wolff, the Mercedes head of motorsport, said.

"We need to do everything we can to continue to beat them."

Wolff revealed that he feared both Hamilton and Nico Rosberg could lose their positions due to a brake issue.

The Austrian said: "It was a huge relief as both cars lost brake power.

"It was a shame for Nico, he was having a great race and did some great overtaking."

Kimi Raikkonen, who finished second for Ferrari on Sunday, promised that the team would win more races after Sebastian Vettel's victory in Malaysia last month, gradually hauling in Mercedes.

The Finn said: "I'm sure we will get there and we can fight every weekend after that. I'm very happy with the team and I think many people didn't expect after last year that we would be in this position this early.

"We will start winning [more] races. We have to be patient and do the same work as we have done so far and we will get there."

While Raikkonen was toasting his first podium finish for 18 months, there was yet more misery for Jenson Button and McLaren. The 2009 champion did not even start the race with an electrical issue.

The team fired the car up, but immediately realised there was a good chance that Button would stop after just a few laps, as he has done in almost every session in Bahrain.

The Englishman, 35, was left to tweet his observations as an online pundit for most of the race. It was an awful end to a miserable weekend, Button's 100th for McLaren no less.

"As u probably are aware I will not b taking part in the Bahrain GP, the guys have worked flat out 2 get the car built but we're unable 2 run," Button tweeted.

"It is the second time this year that a McLaren car has not taken a place on the grid, with the stand-in driver Kevin Magnussen's engine blowing up on the parade lap in Australia.