That came on lap 34 but the leader's pace had not been enough, as Barrichello was already through by the time the McLaren appeared at pit exit, and Button did enough on the run to the first chicane to claim a vital fourth.
Raikkonen was back in the lead, but no doubt suffering a case of déjà vu
as a Force India again dogged his wheeltracks. Just as former team-mate Giancarlo Fisichella had done two weeks earlier, so Sutil refused to be shaken off by the Ferrari driver. Similarly, as it had done at Spa, the Silverstone team called its pit-stop at exactly the same time as the Scuderia - and could have benefited from another Ferrari hiccup.
Raikkonen's stop had gone smoothly until the very end, when the fired-up Finn reacted to the slightest movement from his lollipop man. Having to lift off again to ensure that the fuel hose had been disconnected, he lost a second or two getting underway again, giving Sutil and Force India the glimpse of fourth. Unfortunately, things were going worse at the other end of the pit-lane, with Sutil having locked up on arrival and bowled a couple of his crew to the ground. Add in a momentary second look at the right front and any hope of gaining a place was gone. The pair resumed order unchanged, but Sutil was never quite as close again.
Neither had managed to get out ahead of Hamilton, and the world champion was already trying to close the gap on Button as the race finally boiled down into a straight fight between the two Britons. Barrichello, meanwhile, was already away at the front, enjoying a near three-second cushion over his team-mate courtesy of his early pace.
With Webber's title hopes beached in the gravel with him, Red Bull's hopes rested with Vettel, but last year's Italian Grand Prix winner wasn't finding life anything like as easy as he had in the rain of 2008. Already struggling for grip early on, the German was in for a ragged afternoon, finally appearing to have lost any hope of a point when he skated wide exiting the second Lesmo with eleven laps to run as he chased Nick Heidfeld for eighth.
With the exception of the Toyotas, who battled intimately over twelfth after Jarno Trulli had been hampered by Kazuki Nakajima at the first chicane, there was little interest away from the front, where Hamilton was closing on Button and Sutil continued to harry Raikkonen. While second may have been beyond his reach entering the last lap, Hamilton was not about to give up easily but, having set a personal best in the first sector, his pursuit ended dramatically at the Lesmos. The McLaren had appeared to have been suffering from wheelspin from time to time, and a wheel on the artificial turf lining the circuit only served to spin the car into the inside tyre wall.
With bits of car and barrier spread across the road, the organisers had little option but to send for the safety car, confirming Brawn's 1-2 but ending Sutil's hopes of maybe annexing another podium for Force India.
Fernando Alonso claimed fifth for the beleaguered Renault team, having also got ahead of Kovalainen, while Heidfeld made up for his engine failure in qualifying by taking two points for seventh. Hamilton's accident also had upside for Vettel, who was promoted to the final scoring place, limiting his losses to Button but probably not enough to realistically harbour too many championship hopes.
Fisichella, second two weeks ago behind Raikkonen's Ferrari, just missed out on scoring anything on his debut alongside the Finn after a solid, but unspectacular, run for the Scuderia, while Nakajima rounded out the top ten.
Barrichello's success narrowed his points deficit to Button to 14 with four races remaining, with Vettel now 26 adrift and all but leaving the rest of the season to the Brawns.