Championship leader Jenson Button was delighted to get one over team-mate and title rival Rubens Barrichello in Sunday's Singapore Grand Prix.

The Brawn GP drivers are locked in a battle for the world title and Button had gone into the weekend with a 14-point lead over Barrichello. The Briton overcame a poor qualifying position to finish fifth and increase his drivers' championship lead to 15 points.

"I'm really happy to get fifth, which sounds crazy with the car that we have," said Button, who started the race in 11th. "This weekend hasn't been quite what we expected so it's good to come through in the race and finish in front of my closest rival in the championship. I am now in the right frame of mind."

Button was two places behind Barrichello on the grid, but the 29-year-old from Frome, Somerset produced a solid drive, making steady progress through the field before eventually leapfrogging Barrichello to claim fifth.

It had not all been easy for Button, however, as he had to be patient during the first stint when the safety car that had been deployed due to a crash between Force India's Adrian Sutil and BMW Sauber's Nick Heidfeld.

That forced him to pit ahead of schedule but Button produced a number of quick laps in his second stint to make up ground on Barrichello.

"The safety car made it very difficult as I still had fuel for a few more laps and should have been able to make up two places at my first stop," he added.

"I had to put in some quick laps before my second stop to close up to Rubens and then we were pushing to catch Sebastian (Vettel) before deciding to save the brakes and settle for the fifth position."

Barrichello, meanwhile, refused to give up on his own world tile hopes despite seeing his team-mate increase his lead.

"It was a pretty eventful weekend for me and a tough race," said the 37-year-old. "It could have been a better weekend but I only lost a point to Jenson in the championship despite everything that happened so I'm staying positive."