Max Verstappen set a marker for his rivals ahead of the United States Grand Prix qualifying with a blistering run in final practice.
The Dutchman set a lap time of a one minute 35.825 to finish three-tenths faster than Charles Leclerc.
The Ferrari driver will take a 10-place grid penalty for changing the ICE and TC on the F1-75, but team-mate Carlos Sainz was only a further tenth back.
Sergio Perez was half a second down on Verstappen, with Lewis Hamilton suggesting the potential for Mercedes to be in the fight with at least the Mexican and the Ferraris with an almost identical lap.
But the session was scrappy with almost every driver making an error due to the gusting wind at the Circuit of the Americas.
Mick Schumacher lost a chunk of time through a gearbox issue early on, though quick repair work from his Haas team allowed the German to return to the track.
Daniel Ricciardo was another driver to require repairs when complaining about an issue with the feeling of his brakes, though McLaren had no data issues to support his claim.
Zhou Guanyu was not as fortunate, missing almost the entirety of the hour as Alfa Romeo battled mechanical gremlins.
Teams were eager to complete plenty of running after effectively losing the whole of FP2 as Pirelli took control for a 2023 prototype tyre test.
When the qualifying simulations did take place, cars were squirming and sliding all over the place as the bumpy track surface and the switch in wind direction, as well as gusts of up to 18mph, caught many out under braking.
Leclerc's best time included a major slide through the esses, with Verstappen's margin largely down to the fact he was the only driver to successfully complete a lap without issue.
Behind the top five, Fernando Alonso led the midfield for Alpine although was over a second off Verstappen's pace. The Spaniard is the fourth driver of the weekend who will take penalty pain for an ICE change.
George Russell struggled his way to seventh ahead of Sebastian Vettel, who continued Aston Martin's fine weekend. The Silverstone-based team's form was backed-up by Lance Stroll in ninth, ahead of Pierre Gasly's AlphaTauri.
McLaren's fight for fourth in the constructors' looks as though it will take a hit this weekend, with Lando Norris and Ricciardo only 12th and 15th fastest.