AUSTIN, USA - Red Bull's Sebastian Vettel dominated the first and second practice sessions ahead of the 2012 US Grand Prix.Vettel, who could clinch his third F1 Drivers' title at the Circuit of the Americas, was on pace at the undulating 5.5km track carved out of the south Texas scrublands.Vettel set the early pace in first session with a best time of 1min38 then improved during the second (1min37.7), despite missing much of the session due to a water leak.Vettel said: "It was slippery this morning and a bit like driving on ice. It wasn't so easy. We had a bit of a problem this afternoon and so couldn't run as much as we wanted, but we got two good runs which is important for tomorrow (Nov 17) and Sunday (Nov 18)."The Red Bull ace's second session time, 0.7 seconds quicker than team mate Mark Webber in 1min38.4, underlined the team's intention to end the title chase in Austin.Red Bull principal Christian Horner said: "It's been a great day for us. It's incredible to see what has been done here."It's a great challenge, it's a great spectacle and hopefully this weekend we can put on a great show for our American fans and public and it will be a race to remember."Ferrari's Fernando Alonso, 10 points behind Vettel, had the third best time in both sessions to keep the pressure on his Red Bull rival.DRIVERS' TRACKMcLaren's Lewis Hamilton, who won the last F1 race held in the USA five years ago at Indianapolis, signaled he was ready to scrap for the victory again recording the second effort in the first session and fourth fastest in the second.Hamilton said: "This is a great drivers' track - it's very tough to pull together three perfect sectors. Overall, we've had a good day. Our main difficulty this morning was switching on the tyres in the cooler conditions."But we'll make some changes overnight - there are definitely some improvements we can make."The morning session, run in front of mostly empty grandstands, produced a few thrills as drivers came to grips on the slick undulating circuit.While the 90-minute practice finished without major incident there were plenty of spins and more than a few forays into runoff areas as drivers tested the limits of the track.Times improved dramatically in the afternoon and so did the crowds offering hope that F1 may have finally found a permanent home in Texas.McLaren team boss Martin Whitmarsh said: "It is an enormously challenging circuit. There are a lot of different corners on this circuit, it is kind an assembly of corners from other circuits and tried everything here."The topography is great, there is something about hills and dips and blind corners which make it very challenging for drivers and makes it look great."'WE'VE COME HERE TO DO A JOB'Despite being a new circuit and the pressure of having a championship on the line, Horner said his team is trying to approach the 2012 US Grand Prix the same way it does every other race.Horner said: "The team's very focused. We're really concentrated on getting the most out of this weekend and trying not to allow other distractions to interfere with our preparation and performance."We've come here to do a job and then the championships will tend to take care of themselves."Our approach here is no different here to any other race. There's obviously a bit more hanging on it than others as we've got to the business end of the championship."2012 United States Grand Prix - Second practice times1 Sebastian Vettel (Germany) Red Bull 1min37.718 2 Mark Webber (Australia) Red Bull 1min38.475 3 Fernando Alonso (Spain) Ferrari 1min38.483 4 Lewis Hamilton (Britain) McLaren 1min38.748 5 Jenson Button (Britain) McLaren 1min38.786 6 Felipe Massa (Brazil) Ferrari 1min39.029 7 Nico Rosberg (Germany) Mercedes 1min39.448 8 Bruno Senna (Brazil) Williams 1min39.531 9 Kamui Kobayashi (Japan) Sauber - Ferrari 1min39.653 10 Michael Schumacher (Germany) Mercedes 1min40.115 11 Kimi Raikkonen (Finland) Lotus 1min40.166 12 Pastor Maldonado (Venezuela) Williams 1min40.230 13 Romain Grosjean (France) Lotus 1min40.286 14 Sergio Perez (Mexico) Sauber - Ferrari 1min40.326 15 Daniel Ricciardo (Australia) Toro Rosso 1min40.435 16 Jean-Eric Vergne (France) Toro Rosso 1min40.516 17 Nico Huelkenberg (Germany) Force India 1min40.700 18 Paul Di Resta (Britain) Force India 1min41.430 19 Heikki Kovalainen (Finland) Caterham 1min42.476 20 Timo Glock (Germany) Marussia 1min42.65221 Vitaly Petrov (Russia) Caterham 1min42.846 22 Charles Pic (France) Marussia 1min43.538 23 Pedro de la Rosa (Spain) HRT 1min44.453 24 Narain Karthikeyan (India) HRT 1min45.114First practice session times 1 Sebastian Vettel (Germany) Red Bull 1min38.125 2 Lewis Hamilton (Britain) McLaren 1min39.543 3 Fernando Alonso (Spain) Ferrari 1min40.337 4 Jenson Button (Britain) McLaren 1min40.528 5 Mark Webber (Australia) Red Bull 1min40.650 6 Felipe Massa (Brazil) Ferrari 1min40.966 7 Nico Huelkenberg (Germany) Force India 1min41.023 8 Kamui Kobayashi (Japan) Sauber - Ferrari 1min41.036 9 Nico Rosberg (Germany) Mercedes 1min41.159 10 Sergio Perez (Mexico) Sauber - Ferrari 1min41.473 11 Paul Di Resta (Britain) Force India 1min41.783 12 Daniel Ricciardo (Australia) Toro Rosso 1min41.825 13 Jean-Eric Vergne (France) Toro Rosso 1min41.833 14 Kimi Raikkonen (Finland) Lotus 1min41.880 15 Romain Grosjean (France) Lotus 1min41.998 16 Pastor Maldonado (Venezuela) Williams 1min42.539 17 Michael Schumacher (Germany) Mercedes 1min42.588 18 Charles Pic (France) Marussia 1min43.288 19 Heikki Kovalainen (Finland) Caterham 1min43.443 20 Vitaly Petrov (Russia) Caterham 1min43.522 21 Timo Glock (Germany) Marussia 1min44.464 22 Bruno Senna (Brazil) Williams 1min44.548 23 Pedro de la Rosa (Spain) HRT 1min46.917 24 Ma Qinghua (China) HRT 1min48.559Stay with Wheels24 for the US Grand Prix weekend.