Nobody was more relieved to see Jenson Button win the Bahrain GP than Ross Brawn, who admits that his team has lost its initial advantage.

Despite the obvious pace of the Brawn GP cars, certainly when compared to Ferrari and BMW, it was clear over the course of the Bahrain weekend that Toyota and Red Bull, in particular, were catching up. Indeed, once the fuel loads were published it became apparent that Red Bull appeared to have the edge, with Chinese GP winner Sebastian Vettel running heavier than any of the other 2009 'big guns' at the front of the grid.

However, a stunning opening lap by Jenson Button, combined with typical ace strategy from 'the man', saw Brawn GP take a convincing win, consolidating its lead in both championships.

Over the course of the next two weeks, however, Brawn knows that he and his team must work flat-out if the early season status-quo is to be maintained.

"We have had no upgrades for the first four races because there was nothing there," said Brawn, according to the Guardian. "Getting to the first race was as much as we could manage and there was nothing in the cupboard. Australia was perhaps one we could only throw away, whereas Bahrain was one we had to win.

"My worry was the engine," the Englishman continues, "because in qualifying it was running too hot. Because it all got thrown together at the last minute, we had underestimated the water cooling. The conditions were so hot in Bahrain that it was compromising the car. During practice, the drivers could only do one fast lap and then they had to cool the car down. When Jenson qualified fourth and Rubens sixth, it wasn't looking good, to be honest."

Referring to his star driver, who now has a 12 point lead in the championship, Brawn added: "I've got no doubts about Jenson's ability to win. The way he is driving, that part is taken care of. It's up to us to produce the performance in the car, do the strategies, and make sure the car is reliable."

Ironically, Brawn's win at the weekend, its third from four races, saw the Brackley outfit equal Honda's all-time GP win tally.