German Red Bull driver Sebastian Vettel finished first in both of Friday's practice sessions for the U.S. Grand Prix, the penultimate Formula 1 race of the 2012 season.
Spain's Fernando Alonso, who drives for Ferrari, was third in Friday's runs.
Vettel, the 2010 and 2011 world champion, leads the Spaniard by 10 points in the battle for this year's title. Alonso won back-to-back F1 crowns in 2005-2006.
Sunday's Grand Prix is being run at the new $400 million Circuit of the Americas in Austin, Texas, a track designed for Formula One racing.
Vettel's best time on Friday was 1 minute, 37.718 seconds, while Red Bull teammate Mark Webber of Australia came second.
Alonso posted a time of 1 minute, 38.483 seconds, just ahead of McLaren's Lewis Hamilton.
Pole positions for the race will be determined by the results of Saturday's third practice session. EFE