Max Verstappen was fastest in final practice for the United States Grand Prix ahead of Red Bull team-mate Daniel Ricciardo.
The Red Bull duo looked strong on Saturday morning ahead of qualifying as Verstappen posted the fastest time of the weekend so far, a 1m36.766, although the Dutchman used all of the track and more.
Ricciardo was second, just over two-tenths back, with the pair utilising the supersoft tyre for their quick laps.
Kimi Raikkonen was third for Ferrari, half a second adrift, with the two Mercedes cars behind.
Whilst fourth for Lewis Hamilton and fifth for Nico Rosberg will be disappointing, their quickest times were set on the slower soft tyre as both had compromised supersoft laps which were abandoned.
Hamilton caught a Sauber as he started his flyer in the closing seconds of the session and Rosberg went slightly wide and chose to pit. They were eight-tenths and a second adrift respectively.
Sebastian Vettel was sixth ahead of Nico Hulkenberg and Valtteri Bottas in eighth.
The McLaren duo of Jenson Button and Fernando Alonso completed the top ten.
The session was interrupted by a single red flag caused by Pascal Wehrlein who span off into the gravel trap. Although he did his best to free his Manor, he eventually climbed out after a tense discussion with his engineer.
Carlos Sainz suffered two punctures, firstly his right-rear followed by his left-rear, with the cause yet unknown, limiting him to just six laps.
