The F1 world championship battle will rumble on through South America as Sebastian Vettel and Fernando Alonso both remain in contention for a third title, despite the German extending his advantage by three points in the USGP.

Vettel appeared on course for a far bigger margin until Lewis Hamilton passed him 14 laps from home at the Circuit of the Americas and, with Mark Webber retiring the second Red Bull, Alonso was able to claim another podium finish to further restrict Vettel's gain. The pair head to Interlagos next weekend split by just 13 points - with rain forecast for the Sao Paulo weekend.

Hamilton's victory wasn't enough to lift him back into third in the standings, as Kimi Raikkonen still had enough in hand to resist the Briton, but added another eight points for good measure. The pair are separated by 16 points going into the final round, so it remains possible for the Briton to end his relationship with McLaren by taking P3 with a repeat performance next Sunday.

Hamilton did leap-frog Webber in Texas, and the Australian is not just two points clear of the second McLaren, after Jenson Button turned twelfth on the grid into fifth at the flag, beating Raikkonen and Lotus team-mate Romain Grosjean in the process. While the Finn holds on to third overall, Grosjean moved up to eighth, after passing Nico Rosberg, whose Mercedes team failed to score for a sixth straight race. Felipe Massa, who finished fourth on the road in Austin, sits seventh overall, while Sergio Perez, who also failed to score again, rounds out the top ten.

Vettel's second place was enough for Red Bull to clinch a third successive constructors' title, while Ferrari remains in danger of also being caught and passed by McLaren, despite getting both drivers home between Hamilton and Button on the road. Just 14 points separate the two powerhouses, with Lotus 51 points behind the Woking outfit, and therefore unable to better its fourth place, even with a 1-2 at Interlagos.

Sauber missed the chance to close in on Mercedes after failing to get either driver into the points, while Nico Hulkenberg did enough to out-score the combined efforts of Williams pair Pastor Maldonado and Bruno Senna to strengthen Force India's hold on seventh overall.

Click here for the full championship standings following the F1 2012 United States Grand Prix.