After heavy rain soaked the Circuit of the Americas overnight, it was a wet circuit that greeted the Formula One drivers for the first practice session of the race weekend. With the fastest times set on intermediates, Hamilton was easily fastest by more than a second.
The 6 laps that Hamilton did were enough to have a comfortable margin over Mercedes team mate Valtteri Bottas. The latter was 1.3s down, but still second fastest.
Both Red Bulls were reasonably close in third and fourth, ahead of the Ferrari duo led by Sebastian Vettel. Carlos Sainz ended up 7th, ahead of Grosjean and Sauber's Leclerc and Ericsson as they completed the top 10.
After most drivers - notably neither Red Bull did - completed exploratory laps on full wet tyres, it was Nico Hulkenberg who was the first to switch to intermediates. It was by then clear this was the better tyre for the conditions, making sure the full wet wasn't seen again during the remaining 78 minutes.
The wet track made sure numerous drivers ended up off the circuit one time or another, but it was only Leclerc who caused a red flag situation. No damage was done to his car though, but the gravel he had kicked up onto the circuit prevented action for the next 11 minutes.
Conditions are expected to be the same in FP2 and for Saturday, with sunny conditions on target for Sunday's race.
|1||44||Lewis Hamilton||Mercedes AMG||1:47.502||-||6|
|2||77||Valtteri Bottas||Mercedes AMG||1:48.806||+1.304s||7|
|3||33||Max Verstappen||Red Bull Racing TAG Heuer||1:48.847||+1.345s||9|
|4||3||Daniel Ricciardo||Red Bull Racing TAG Heuer||1:49.326||+1.824s||9|
|8||8||Romain Grosjean||Haas Ferrari||1:50.821||+3.319s||10|
|9||16||Charles Leclerc||Sauber Ferrari||1:50.961||+3.459s||14|
|10||9||Marcus Ericsson||Sauber Ferrari||1:51.016||+3.514s||14|
|11||14||Fernando Alonso||McLaren Renault||1:51.036||+3.534s||9|
|12||47||Lando Norris||McLaren Renault||1:51.232||+3.730s||9|
|13||10||Pierre Gasly||Scuderia Toro Rosso Honda||1:51.234||+3.732s||19|
|14||11||Sergio Perez||Force India Mercedes||1:51.459||+3.957s||18|
|15||35||Sergey Sirotkin||Williams Mercedes||1:51.589||+4.087s||14|
|16||20||Kevin Magnussen||Haas Ferrari||1:51.614||+4.112s||15|
|17||31||Esteban Ocon||Force India Mercedes||1:51.655||+4.153s||17|
|19||18||Lance Stroll||Williams Mercedes||1:51.896||+4.394s||14|
|20||38||Sean Gelael||Scuderia Toro Rosso Honda||1:52.625||+5.123s||21|