The delays and disruption meant a sense of the competitive picture was only partially formed, especially as there was no time for the race simulation runs that normally take place in the final minutes of the session.
For what it’s worth, Sauber’s Nico Hulkenberg was fourth fastest, ahead of the Racing Bulls of Isack Hadjar and Liam Lawson.
Mercedes’ George Russell was seventh fastest, with Williams’ Alex Albon, Verstappen and Hamilton completing the top 10.
Antonelli continued the strong form that saw him score a second-place finish in Brazil two weeks ago for Mercedes, who started the weekend favourites after Russell’s dominant victory last year.
But Russell cautioned against presuming the team could repeat the same feat this year.
“We’re in the mix,” he said. “There were a lot of expectations on us coming into this weekend but we’ve changed the car a lot since last year and it’s definitely made it a better car over the course of a season but maybe hasn’t made it as competitive as we were here 12 months ago.
“But we’re still there or thereabouts. It was close. Lando was quick, Verstappen and Leclerc were quick in P1, Kimi was quick, so it’s going to be close.”
Verstappen was fourth fastest in the first session, 0.307secs off pace-setter Leclerc and highly unusually behind team-mate Yuki Tsunoda. He said: “It has been OK, just difficult to understand what to do with these interruptions.
“We still need to improve a little bit of find a bit more grip. The track’s improving every session and we will try to focus on that, seeing how far we can operate the tyres for qualifying and the race.”
Verstappen was also tipped strongly coming into the race meeting as he won at Monza and Baku in September, both tracks with similar characteristics to Las Vegas, high-speed straights into big braking zones and slow-speed corners, with relatively low grip.
But Verstappen said the circuits were less comparable than appeared at first glance.
“It’s a lot colder here and the surface is very slippery so you cannot compare them to other tracks just because it’s low downforce,” he said. “So it’s not a given you will be quick here.”
Shortly before the second red flag, Leclerc’s Ferrari stopped on track with what appeared to be a gearbox problem.
