Brawn's second one-two of the season

It was a sign of the changing times in 2009 that Lewis Hamilton, the reigning world champion, was lapped by Jenson Button, the heir apparent, on the penultimate lap, writes Maurice Hamilton.

While waiting for the podium ceremony to begin, Rubens Barrichello flopped on to a settee and asked no one in particular: "How did I lose that race" Jenson Button sat down beside his team-mate and was unable to provide an instant answer. The Brawn-Mercedes drivers had just scored their second one-two of the season but Barrichello's bemused look indicated that he rather than his colleague should have been preparing to stand on top of the podium for the first time in 2009.

Button's fourth win of the season had arrived thanks to a change of pit-stop strategy for the Englishman and a tyre problem for the Brazilian at a critical stage. Until then, Barrichello appeared to be in command of the fifth round of the championship and a win for him would have reduced Button's lead from 14 points to 10 with 12 races to go.

The championship is still far from over, but Barrichello saw this as a lost opportunity to keep in touch before a point is reached later in the season when the mathematics will dictate that one Brawn driver should be favoured over the other. Until then the team principal, Ross Brawn, insists that it is every man for himself.

"You only had to see the first corner for proof of that," said Brawn, referring to the fact that Barrichello started from third on the grid and not only passed the Red Bull of Sebastian Vettel but also ran around the outside of Button.

Barrichello thought he had it made. He knew he was carrying more fuel and would run for a lap longer before the first pit stop, a clear advantage that would deny Button any chance to overtake. Everything appeared to be going according to plan when they made their respective stops, on laps 18 and 19, but unknown to either driver, Brawn had switched Button's strategy from three stops to two.

"We had worked out that three stops would be the quickest," said Brawn. "But when we saw that Jenson was likely to get caught in traffic, we put in more fuel for a long middle stint and just two stops."

Having been told of the change, Button had to adjust his driving style.

"Initially I didn't think it was a good idea," he said. "I was worried about coming out behind (Felipe) Massa, because if I got stuck behind him I would have been in trouble. But the team realised I had enough in hand to stay ahead of the Ferrari. The car suddenly felt very, very heavy. I was then told to push really hard. I have never driven in that way before and it probably looked pretty messy, but it was the only way to get time out of the car."

Button took a lead he would not lose when Barrichello made his second stop, on lap 31. Barrichello, meanwhile, was not helped by a set of tyres that upset the handling of his car.

"Jenson's performance on heavy fuel in the middle stint was critical," Brawn said. "Equally, Rubens seemed to have a set of tyres that caused problems. That was the crucial bit of the race and Jenson took the opportunity. If Rubens hadn't had that problem, it would have been really close. At one stage he was one second ahead when forecasting the outcome. My one dread was going to be after the last pit stop, when Rubens would rejoin and they would be next to each other going into the first corner. There would have been nothing in it."

The potential drama within the team deflected the fact that Brawn continue to have an edge despite the opposition's attempts to catch up since the previous race in Bahrain. Red Bull continue to offer the most serious competition even though it was Mark Webber rather than Vettel who finished third. Vettel's race had been compromised by Barrichello's fast start and Felipe Massa using his Kers power-boost to move his Ferrari ahead of the Red Bull on the run to the first corner. Massa, the Brazilian, would have finished fourth had he not been forced to conserve fuel and thus drop to an eventual sixth place in the closing laps.

A pressure problem within the car's tank meant that not all the fuel had gone on board at the last stop, a rare problem that detracted from a major improvement for Ferrari.

McLaren could make the same claim. Lewis Hamilton finished out of the points in ninth place after being delayed briefly by spinning cars and a collision at the first corner.

"Today was a difficult race for me because we lack the downforce of the top cars," said Hamilton. "I was a bit worried about my tyres after driving over so much debris at the first corner but I came out of it OK.

"It was a tough, long race and it was incredibly hard to keep the car on the road - it felt like driving on ice at times. I gave it 100% for the entire race, so ninth place doesn't feel like the proper reward for the team. We're hopeful that Monaco will be a better race for us because the absence of fast corners shouldn't hurt us as much as it did here."

It was a sign of the changing times in 2009 that Hamilton, the reigning world champion, was lapped by Button, the heir apparent, on the penultimate lap.