Sebastian Vettel bounced back to top the times as he and Kimi Raikkonen delivered a Ferrari one-two in Saturday's third and final free practice for Sunday's United States Grand Prix.
Vettel, who had struggled in Friday's rain-swept wet sessions when he was also handed a three-place grid penalty, showed he and his team remain defiant in their bid to keep the championship alive.
The four-time champion clocked a fastest lap in one minute and 33.797 seconds to outpace his Sauber-bound team-mate by 0.046 seconds.
Vettel and Ferrari need to dominate qualifying later Saturday if possible to give him any realistic chance of victory.
Championship-leading Lewis Hamilton, who needs to outscore Vettel by eight points to clinch his fifth world title, was third for Mercedes 0.073 seconds adrift of the best time.
His Mercedes team-mate Valtteri Bottas was fourth, seven-tenths of a second further back, ahead of the two Red Bulls of Max Verstappen and Renault-bound Daniel Ricciardo.
Charles Leclerc was seventh for Sauber ahead of Sergio Perez of Force India, Carlos Sainz for Renault and Romain Grosjean of Haas.
After Friday's rain, the session delivered a welcome dry and incident-free 90 minutes of action at the Circuit of the Americas where Hamilton has won five of the six races held to date.
© 2018 AFP