On a United States Grand Prix weekend on which he can seal his fifth Formula 1 world championship title, Lewis Hamilton began his preparations in style, dominating a wet opening practice session at Austin’s Circuit of the Americas to finish 1.3 seconds clear of Mercedes team-mate Valtteri Bottas.

Behind the Mercedes pair, Red Bull’s Max Verstappen and Daniel Ricciardo were the Silver Arrows’ closest challengers, while Hamilton’s only real title rival, Sebastian Vettel ended the session in fifth place, almost two seconds off the championship leader’s pace.

Heavy rain in the morning led to a cautious start to the session, with most drivers restricting themselves to reconnaissance laps to test the conditions and thus an absence of lap times in the opening third of the session.

Track conditions eventually improved to the point that intermediate tyres became an option and in those circumstances Red Bull initially led the way, with Ricciardo leading Verstappen with a lap of 1:50.642s.

Ricciardo improved on that but then Mercedes driver Bottas took to the track and he swiftly took over at the top of the timesheet when he posted a time of 1:48.806.

Soon after the action ground to a halt when Sauber’s Charles Leclerc brought out the red flag.

The Monegasque driver went off track at Turn 9 but in rejoining from the gravel trap he spread inadvertently spread a large number of stones on the track, and with the debris requiring removal the session was stopped for 10 minutes.

When the green lights were once again shown, Hamilton vaulted to the top of the timesheet with his eventual session-best lap of 1:47.502. That put him 1.3s clear of Bottas and Verstappen and 1.8s ahead of fourth-placed Ricciardo.

Ferrari, meanwhile, appeared to target long runs, with both Vettel and team-mate Kimi Räikkönen posting more than double the amount of laps turned by the Mercedes and Red Bull driver. As such neither Ferrari driver made any real impact at the top of the timesheet. Vettel finished with a best lap of 1:49.489 that put him just over four tenths of a second clear of Räikkönen.

Best of the rest status in the opening session was claimed by Renault’s Carlos Sainz, with Haas’s Romain Grosjean in eighth place ahead of the Saubers of Leclerc, who recovered from his early spin, and Marcus Ericsson.

McLaren’s Fernando Alonso ended the session in 11th place, just under two tenths of a second clear of his 2019 replacement, Lando Norris. Both drivers were more than 3.5s off the pace.

2018 Formula 1 United States Grand Prix – Free Practice 1
1 Lewis Hamilton Mercedes 6 1:47.502
2 Valtteri Bottas Mercedes 7 1:48.806 1.304
3 Max Verstappen Red Bull Racing 9 1:48.847 1.345
4 Daniel Ricciardo Red Bull Racing 9 1:49.326 1.824
5 Sebastian Vettel Ferrari 18 1:49.489 1.987
6 Kimi Raikkonen Ferrari 20 1:49.928 2.426
7 Carlos Sainz Renault 8 1:50.665 3.163
8 Romain Grosjean Haas 10 1:50.821 3.319
9 Charles Leclerc Sauber 14 1:50.961 3.459
10 Marcus Ericsson Sauber 14 1:51.016 3.514
11 Fernando Alonso McLaren 9 1:51.036 3.534
12 Lando Norris McLaren 9 1:51.232 3.730
13 Pierre Gasly Toro Rosso 19 1:51.234 3.732
14 Sergio Perez Force India 18 1:51.459 3.957
15 Sergey Sirotkin Williams 14 1:51.589 4.087
16 Kevin Magnussen Haas 15 1:51.614 4.112
17 Esteban Ocon Force India 17 1:51.655 4.153
18 Nico Hulkenberg Renault 7 1:51.717 4.215
19 Lance Stroll Williams 14 1:51.896 4.394
20 Sean Gelael Toro Rosso 21 1:52.625 5.123