AUSTIN -- Lewis Hamilton put down an immediate marker to his U.S. Grand Prix rivals with a time half a second quicker than Sebastian Vettel in opening practice.
Hamilton has an outside shot of securing a fourth world championship this weekend if he out-scores Vettel by 15 points. The Englishman is heavily favoured to take the race victory, at least: he has won all but one of the races held at the Circuit of the Americas since it joined the F1 calendar in 2012, while Mercedes has excelled in Austin since the introduction of V6 turbos two years later.