Max Verstappen has ended the sole practice session at the United States Grand Prix as the fastest driver ahead of qualifying.
With Formula 1’s Sprint format in play this weekend, the drivers had just 60 minutes of practice running at the Circuit of the Americas.
Drivers mainly utilised the Medium compound for much of the session, however a switch to Softs came in the final moments as the competitors dialled themselves in ahead of qualifying.
Verstappen’s fastest lap time was a 1:35.912, registering one and a half tenths ahead of Ferrari's Charles Leclerc and Mercedes' Lewis Hamilton.
Sergio Perez classified in fourth place, three-tenths down on his session-topping team-mate while Kevin Magnussen impressed in the upgraded Haas to go fifth ahead of George Russell.
Result Free practice 1 - United States
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Stroll struggles continue
Drivers highlighted the bumpy nature of the circuit throughout the session, something that has been an issue in the past at the COTA.
Some were also struggling at Turn 12 as several ran wide and into the run-off following a snap of oversteer through the corner.
Lance Stroll only managed five laps before he was called back into the pit lane as Aston Martin detected a problem with his front brakes.
It was soon discovered that the car was suffering from high brake temperatures which sidelined the Canadian for the remainder of the session.
Piastri had an uncomfortable moment at Turn 9 after clipping the inside kerb which pitched the car into the grass and gravel, forcing the Australian to battle the car to keep it pointed straight.
The rookie and his McLaren team-mate Lando Norris opted not to switch to the Soft tyre at the end of the session and finished outside the top 10.
Alexander Albon was seventh, leading the second Ferrari of Carlos Sainz. Nico Hulkenberg was ninth, while Pierre Gasly rounded out the top 10 for Alpine.