Verstappen is the first to complete a performance run on soft tyres and unsurprisingly goes top of the pile with a 1m33.855s. That puts him 0.862s clear of Sainz's time, which was set on hards.
Perez, who runs at the same time as Verstappen, ends up eight tenths slower than his Red Bull teammate. That leaves him third, behind Sainz's Ferrari.
Leclerc has put his Ferrari back on top with a new benchmark time (1m34.966s) on hard tyres.
He's 0.265s clear of teammate Sainz, while Russell is third, nearly half a second adrift.
What is going on with the Mercedes? It looks a real handful out there in the early stages of FP1.
Minutes after Hamilton was caught out at Turn 4, Russell goes for a (much slower) spin at Turn 1.
Hamilton is the next to spin, and it's a huge one!
The seven-time world champion goes for a spin in the high-speed first sector. He was changing direction when his Mercedes suddenly snapped at him at Turn 4, with the Haas of Hulkenberg on his outside.
âWhen I come in you need to check these damn tyres, and check the floor [for damage]," reports Hamilton, who recovered the spin and was able to avoid hitting any barriers.
Bizarrely, the other Mercedes of Russell says he just had a "moment" through the same corner.
Yellow flags are briefly flown as Gasly spins his McLaren-esque coloured Alpine at Turn 1, before carrying on his way without further drama.
"I just lost it on braking," the Frenchman explains.
Verstappen has jumped to the top of the timesheets with a 1m35.538s as times continue to improve early on here.
That puts the Red Bull driver 0.322s clear of Russell, and half a second clear of Leclerc. Sainz and Norris round out the top five.
The fastest times so far have all been set on the hard tyre.
Leclerc is fast out of the blocks for Ferrari, posting a 1m36.724s to hold the early benchmark, just 0.001s clear of McLaren's Norris.
We have a green light at the end of the pit lane, signalling the start of the only practice session of the weekend at COTA.
The build up to the weekend has been dominated by chatter surrounding a contentious ride-height device on Red Bull's RB20.
Red Bull have agreed to make changes to their car after discussions with F1's governing body the FIA, who have moved to clampdown on the mechanism amid suspicion and concern raised by rivals.
Here we explain everything we know about Red Bull 'bib' furore in Austin.
The United States Grand Prix marks the start of a run of two triple headers featuring six grands prix - and three sprint races - to determine the outcome of the 2024 world championships.
Max Verstappen, who is winless in eight races, holds a 52-point lead over Lando Norris and his resurgent McLaren squad who currently boast the car to beat.
Meanwhile, in the constructors' championship, McLaren head Red Bull by 41 points.
Will Norris continue to eat into Verstappen's championship lead this weekend in Austin?
Howdy and welcome to Crash.net's live coverage of the 2024 United States Grand Prix.
After a three-week break, F1 returns to action today at COTA with an hour of practice followed by the return of sprint qualifying later this evening.
We will keep you up to date with all of the action!
