"It was such a warm welcome and one of the best, if not the best, race of the year - especially for me and the team," added 2008 champion Hamilton, wearing a cowboy hat on the podium, who is moving to Mercedes at the end of the season.
"It's been a long time since we had a win. I'm so proud of the team and grateful for the support we've had."
While Vettel and Red Bull team mate Mark Webber got away quickly, Alonso made his move and was fourth after the first corner.
Image: McLaren Mercedes driver Lewis Hamilton's, of Britain, hat sits on the trophy after he won the Formula One U.S. Grand Prix auto race at the Circuit of the Americas Sunday, Nov. 18, 2012, in Austin, Texas.