Russell lapped the high-altitude Autodromo Hermanos Rodriguez with a quickest lap of one minute 18.399 seconds, 0.144 faster than fellow Briton and seven-times world champion Hamilton.

Red Bull's double world champion Max Verstappen was third quickest in a bright and sunny session but 0.477 off Russell's time.

Both titles have been decided, with Red Bull taking the constructors' championship in Austin last weekend with three races to spare and Verstappen retaining his drivers' crown at the previous round in Japan.

There is still plenty at stake, with Mercedes chasing a first win of the season and Hamilton hoping to end the longest victory drought of an F1 career in which he has won a race every year since 2007.

Verstappen has his eyes on a Formula One record with a 14th win of the season while team mate Sergio Perez, fifth in Saturday's session, can become the first Mexican to win his home race.

Ferrari's Charles Leclerc, preparing for his 100th race start, was fourth fastest. He and Perez are locked in a close battle for second overall.

Ferrari's Carlos Sainz lapped sixth fastest with Lando Norris seventh for McLaren and Alfa Romeo's Valtteri Bottas eighth.

Kevin Magnussen will have a five-place grid penalty after qualifying for having a new engine in his Haas while Aston Martin's Lance Stroll carries a three-place drop as punishment for causing a collision in Austin.