Lewis Hamilton leads the first trials of the US Grand Prix

Lewis Hamilton began his US Grand Prix weekend while he intends to continue the momentum with record breaking time in a first wet test session.

The Mercedes driver, who can win a fifth title on Sunday, was 1.3 seconds ahead of teammate Valtteri Bottas.

Hamilton will be champion if he scores eight points more than Sebastian Vettel of Ferrari, fifth, at almost two seconds of pace.

Vettel was summoned by the stewards for not having slowed down the red flag.

If found guilty, previous suggests that could be a grid penalty of three places.

Max Verstappen and Daniel Ricciardo of Red Bull finished third and fourth.

The day began with torrential rains in South Texas, but the situation had eased at the start of the first 90-minute session and the cars were able to run from the start.

Red Bull set the tone early before Bottas replaced them, but Hamilton moved the posts in his second round.

The Finn was on a lap that would have been closer to Hamilton, but who stood up before the end of the race and did not run anymore.

The Ferraris have run a lot more than Mercedes – Hamilton has only completed six laps in total and only two laps, while Vettel and Raikkonen have traveled 17 and 19 laps each.

Ferrari has an aerodynamic improvement during this race, while it's trying to recover some of the lost performance against Mercedes in recent races.

The rainy weather should continue throughout the day, with a 60% chance of rain for the second session, which will begin at 14:00 local time (20:00 UK time).

Behind Kimi Raikkonen's Ferrari in sixth place, Carlos Sainz of Renault was at the head of Formula 1 "class B", Romain Grosjean's Haas and Sauber's Charles Leclerc.

Leclerc caused a red flag midway through the session when he turned back at Turn Eight and extended gravel on the track at the Turn Nine exit as he joined the track.

Outside the top 10, the Briton Lando Norris was only 0.196 seconds behind McLaren's teammate Fernando Alonso. Aged 18, who had signed to compete for McLaren in 2019, he replaced regular driver Stoffel Vandoorne in the opening session.