Three-time F1 champion Max Verstappen again set the pace albeit in a first practice session for the Mexico City Grand Prix overshadowed by numerous technical issues up and down the pitlane.
Even Verstappen, who set the fastest lap with a time of one minute 19.718s, had to pit at one stage after complaining about “something loose” in the footwell of his Red Bull.
Fourth quickest Lando Norris, half a second behind Verstappen in his McLaren, encountered a problem with his rev limiter as he pulled out of the garage and into the pitlane.
Overall, it was a fascinating session that saw Williams’ Alex Albon finished second quickest, just 0.095s off of the leading time, as the high altitude of the Autodromo Hermanos Rodriguez played its part given the effect it has on the power unit and cooling systems especially given there is 22 percent less air.
Ferrari’s Carlos Sainz and Daniel Ricciardo in his AlphaTauri encountered issues of a different nature, however, in the opening 15 minutes.
For AlphaTauri driver Ricciardo, as the Australian powered down the main straight, a part of the AT04 flew off – understood to be a piece of the car’s heat shield – landing on the middle of the track, just off the racing line.
Surprisingly, despite the positioning of the bodywork, it took a full minute before the yellow flags were waved to make the drivers aware of a problem. Ricciardo went on to finish a superb eighth.
A few minutes later, Sainz, already feeling unwell which resulted in him skipping his usual media duties at the track on Thursday, was left worse when he lost the hydraulics on his SF23.
Unable to change gear and with no power steering, Sainz was fortunate to return to the garage to enable his team to investigate the cause of the concern but were at least able to send him back on track, finishing seventh, 0.761s down.
In terms of the timesheet, home hero Sergio Perez delighted his legion of fans by setting the first competitive time with a lap of 1:21.596s on the medium but had to settle for third best on the softs, 0.297s adrift.
Behind Norris in fourth was Charles Leclerc in his Ferrari and the second McLaren of Oscar Piastri, who remarkably set his best lap time on a prototype medium being run by Pirelli for this session for evaluation ahead of a possible introduction for 2024.
Behind Ricciardo, Alpine’s Esteban Ocon and Lance Stroll in his Aston Martin completed the top 10.
As for the second Aston Martin of Fernando Alonso, he had only run for two installation laps when he was forced to pit to allow his crew to carry out checks on the AMR23 that consigned him to the garage for half of the session, and down in 16th by the end.
A quarter of the teams used this session to carry out mandatory run-outs for a rookie, with four of the top six in the F2 championship on track.
For championship leader Theo Pourchaire, his session was riddled with issues that resulted in him being unable to set a timed lap in the Alfa Romeo of Valtteri Bottas.
The Frenchman was left at the bottom of the timesheet whilst his team carried out repairs on a suspected brake-by-wire failure.
Second-placed Fredrik Vesti, in for George Russell at Mercedes, was the slowest of the 19 drivers to set a time, albeit executing a likely definitive run plan from the team. Seven-time F1 champion Lewis Hamilton was 11th, a full second down.
At Alpine, fourth-placed Jack Doohan delivered a solid session to finish 18th on the timesheet, with a best lap of 1:22.109s as he stood in for Pierre Gasly.
Sixth-placed Oliver Bearman was the best of the juniors, claiming 15th in the Haas of Kevin Magnussen.
Isack Hadjar, a Red Bull junior who has disappointed this year as he is a lowly 14th, ran with a new power unit in the AlphaTauri that will mean a grid penalty for Yuki Tsunoda. Hadjar finished 17th quickest.