| Lewis Hamilton took his second consecutive Grand Prix victory at Indianapolis and extended his championship lead to ten points over Fernando Alonso after a race-long battle with his McLaren teammate.
Pole-sitter Hamilton had held onto the lead at the start despite some concerted probes from Alonso on the opening lap.
He then proceeded to edge away and establish a three-second advantage before the first pitstops, with Hamilton coming on a lap ahead of the Spaniard on lap 21.
But in the middle stint Alonso rapidly closed on Hamilton, especially once they hit the long train of traffic that was trying to pass Vitantonio Liuzzi.
On lap 38 the two McLarens were absolutely nose to tail, with Alonso drafting Hamilton onto the pits straight and lining up a pass at Turn 1.
Hamilton defended the inside and Alonso could not complete an outside line pass, but the incident appeared to frustrate Alonso, who veered across the track to run very close to the McLaren pit wall on the following lap.
Alonso then made his final stop a lap ahead of Hamilton, rejoining two seconds adrift and having to follow his teammate to the flag.
Ferrari were not quite on McLaren's pace again, with Felipe Massa and Kimi Raikkonen finishing close together in third and fourth, 13 seconds behind the leaders.
While Massa held a lonely third for most of the race, Raikkonen had to fight back after dropping to sixth at the start.
He spent his opening stint trapped behind Nick Heidfeld and Heikki Kovalainen, but put on a charge after switching to soft tyres at his first stop - setting the fastest lap of the race as he gained on Massa.
Kovalainen followed up his Canadian Grand Prix success with a strong fifth place, having led for several laps thanks to his long first stint.
Nico Rosberg was set for sixth, having used a one-stop strategy to progress from 14th on the grid, but he pulled off in a cloud of smoke with four laps remaining.
With Heidfeld also retiring with apparent hydraulic problems, the battling Jarno Trulli, Mark Webber and Sebastian Vettel moved up to sixth, seventh and eighth.
That made 19-year-old Vettel the youngest ever F1 points-scorer, beating the record set by Jenson Button in 2000.
The German had lost several places with a trip across the grass at the start, but drove a steady race on his debut and often matched teammate Heidfeld's times.
In the final laps he closed right in on the battle between one-stopper Trulli and the two-stopping Webber, whose spirited dice for sixth saw the Red Bull skitter over the Turn 1 grass after a failed move down the inside.
Giancarlo Fisichella could only manage ninth after a spin on the second lap. He finished ahead of Alex Wurz, who lost a lot of time trapped behind Liuzzi early on.
The race saw far less drama than last week's Canadian event, but a first corner crash accounted for several competitors, as Ralf Schumacher veered into Rubens Barrichello and David Coulthard under braking, putting all three out.
Jenson Button was set briefly airbourne in the chain-reaction, but continued to finish 12th, being passed by Anthony Davidson in the final laps.
Davidson's Super Aguri teammate Takuma Sato spun off before he could be penalised for passing under yellow, so will receive a ten-place grid penalty at the French GP.
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