Kimi Raikkonen upstaged the established order to claim a resounding victory for Lotus in the season-opening Australian Formula One Grand Prix in Melbourne on Sunday.

The taciturn Finn roared off from seventh on the starting grid to take a forward position, and employed a strategy of only two stops to take the race from Ferrari's Fernando Alonso and Red Bull world champion Sebastian Vettel. For Raikkonen, 33, who won the 2007 world championship with Ferrari before taking two years out to drive in rallying, it was his 20th GP triumph.

It was the Finn's second triumph when he won the 2007 Australian race on his way to securing the world drivers' title. Raikkonen had the luxury of an easy run in the closing laps to the finish line and beat Alonso by 12.4secs, with Vettel a further 9.8secs away in third. Alonso's Ferrari teammate Felipe Massa of Brazil was fourth, with Britain's Lewis Hamilton in a Mercedes fifth and Australian Mark Webber in a Red Bull sixth.

Raikkonen won the race despite only coming into the pits for two tyre changes compared to three employed by his rivals. It was a great day for the legendary Lotus, which took over the Renault team last year when Raikkonen won the Abu Dhabi GP near the end of the season.

"I believe my car is quite good, it's been feeling good all weekend and when we did the longer run it felt good," Raikkonen said. "We knew that if the front tyres were lasting we would be fine. I was confident, but you have to get through the start and the first lap and it's the first race, so you never know what's going to happen. I felt I had the car and it turned out to be pretty good."

Vettel, who had the fastest car from qualifying and started off the pole, said tyre degradation cost him his chance of victory as he searches for his fourth straight world championship this season. "Clearly when you start from pole you want to win as well but we could see after a very good start and after the first two or three laps the tyres were starting to fall apart and we couldn't go as long as other people," Vettel said.

Alonso said that after difficult starts for Ferrari over the previous two seasons he was delighted to get onto the podium in the season-opener. "This year it feels very different and we feel much more optimistic and the car is responding well, we are competitive, so we have a very interesting season ahead of us."

The 2008 world champion Hamilton, having his first race with Mercedes after splitting with McLaren, said his fifth place was better than his new team had expected coming to Australia. "The car felt really good out there. I had a strong first stint and was able to make the supersofts (tyres) last longer than most of the others," Hamilton said.

"The important thing is that we have a car that we can really work with and the team have done a fantastic job to get us to this position, and now we'll look forward to Malaysia next weekend and hopefully build on this positive start."

Eighteen cars finished the 58-lap race around the Albert Park street circuit with two retirements by Nico Hulkenberg and Daniel Ricciardo, while Nico Rosberg and Pastor Maldonado both encountered car trouble and could not rejoin the race. The second race will be at Sepang in Malaysia next weekend.