Hamilton on top in Vegas ahead of Norris as Verstappen struggles
Hamilton clocked a best lap in 1min 33.825sec in his Mercedes to outpace fellow Briton Norris in a McLaren by 0.011 seconds. Hamilton's Mercedes’ team-mate George Russell was third.
Norris is bidding to keep his faint title challenge alive but Verstappen, aiming to clinch his fourth consecutive drivers' world title, made little impression in a cold and somewhat desultory session and finished the session more than two seconds adrift of the pace.
He leads Norris by 62 points with three Grands Prix remaining and will take his fourth title on Saturday if he finishes ahead of Norris or emerges with at least a 60-point advantage.
The Ferraris of Carlos Sainz and Charles Leclerc were fourth and fifth ahead of Alpine’s Pierre Gasly, Kevin Magnussen of Haas and Oscar Piastri in the second McLaren.
Nico Hulkenberg was ninth in the second Haas and Yuki Tsunoda 10th for RB while the Red Bull pair wound up 17th, with Verstappen, and 19th with Sergio Perez.
On a cold and dry night in the Nevada desert, the second session began in dusty low-grip conditions, Hamilton having led Russell at the top of the opening hour for Mercedes.
That led team boss Toto Wolff to quip that the 'silver arrows' were the "dirty track champions" and they resumed in similar style until Leclerc took control after 20 minutes ahead of Russell.
Russell responded after 28 minutes after switching to softs from mediums with a lap in 1:34.015, four-tenths clear of the Monegasque driver and good enough to resist Hamilton’s lap by two-tenths as the Mercedes pair continued to shine.
Ferrari's switch to softs saw Sainz rise to second before Norris clocked 1:33.836 to go top ahead of Russell by nearly two-tenths followed by Hamilton, relishing the rare conditions, took over in 1;33.825.
A red flag interrupted the action with 21 minutes remaining when Williams’ Alex Albon pulled up with fuel system problems leading to a six-minute delay as his car was towed behind the barriers by the marshals.
At this stage, Verstappen remained on mediums and was down in 17th, clearly not chasing a simulated qualifying lap time as Red Bull struggled for grip. Team-mate Sergio Perez was 19th.
Ferrari also switched back to mediums to do longer runs in race simulation mode as did Red Bull, decisions that may pay dividends, but for Hamilton it was a welcome return to form after a difficult outing at the Sao Paulo Grand Prix.