Lewis Hamilton fastest in United States GP practice
Lewis Hamilton started his United States Grand Prix weekend in the best possible way with an impressive performance in first practice.
Hamilton, who must beat Mercedes team-mate Nico Rosberg at the Circuit of the Americas on Sunday to close a 33-point deficit, was comfortably fastest.
The world champion ended up 0.315 seconds quicker than Rosberg after being fastest throughout the session.
Red Bull's Max Verstappen was third fastest but two seconds off the pace.
The Dutchman, however, set his fastest time on the medium tyre while Mercedes used the soft, which is in the region of a second a lap faster.
The second session starts at 20:00 BST.
Hamilton on a mission
Hamilton started the weekend as if he means business, after a shaky series of races that have seen Rosberg take a stranglehold on the championship.
Had Hamilton not had an engine failure while leading in Malaysia, he would be pretty much neck-and-neck with his team-mate.
But that problem, coupled with below-par races in Singapore and Japan, have left him without control of the championship.
With a maximum of 100 points available over the remaining four races, Rosberg can afford to finish second to Hamilton at all of them and still become champion.
But Hamilton says he will "give it everything I've got and still believe everything is possible" and he came out in first practice as if he meant it.
On the Mercedes drivers' first runs, done on super-soft tyres, Hamilton was a second faster than Rosberg on their first laps, half a second quicker on their second runs and 0.3secs quicker on their third laps.
He then maintained his superiority on their second runs on the soft tyres in a session held in beautiful Texan autumn sunshine but a strong wind.
The others a mile off so far
Verstappen's third fastest time was an impressive lap on the medium tyre, while Ferrari's Kimi Raikkonen in fourth was 0.028secs adrift on the soft tyre.
Trailing them by 0.3secs and separated by a similarly tight margin were the Force India of Nico Hulkenberg, who it was announced earlier this week would be joining Renault next season, and Valtteri Bottas' Williams.
Red Bull's Daniel Ricciardo was seventh and a chunky 0.6secs slower than Verstappen. Some, but not all, of that margin was accounted for by a difference in engine performance.
A new British face
Englishman Jordan King made his grand prix weekend debut for the Manor team and was 19th fastest on the soft tyre.
That put him 1.8secs quicker than team-mate and regular race driver Esteban Ocon, who ran only on the medium tyre.
Jenson Button was 18th for McLaren, with team-mate Fernando Alonso 13th.