Max Verstappen flew around the circuit in Texas to finish fastest in FP3 as the big guns get ready for qualifying proper later this evening.
The Dutchman finished ahead of Sebastian Vettel who led for much of the session, and Lando Norris put in a superb run to finish in third spot ahead of both Mercedes.
It was a better session for Vettel than it was for his team-mate Charles Leclerc, who limped out of after suffering engine issues, with smoke bellowing from his car, and he failed to record a time at all as the engineers worked tirelessly to get him ready for qualifying.
Mercedes looked as if they were keeping something back for the qualifying session, with Valtteri Bottas and Lewis Hamilton finishing P4 and P5 respectively.