Max Verstappen completed a clean sweep of practice sessions for the Mexican Grand Prix but faced a sterner challenge from Red Bull’s rivals.
Verstappen led team-mate Daniel Ricciardo during both of Friday’s sessions as the pair finished over a second clear of their opponents.
But in cool and cloudy conditions at the Autodromo Hermanos Rodriguez on Saturday, following overnight rain that led to a quiet first half of FP3 as the circuit dried, Red Bull’s rivals closed in.
Lewis Hamilton and Sebastian Vettel finished second and third respectively, Hamilton 0.254s down on Verstappen's 1:16.284 benchmark, with the Ferrari driver just 0.028s further behind his title opponent.
A poor final sector consigned Ricciardo a low-key fourth, while Austin victor Kimi Raikkonen was also adrift of his team-mate as he classified fifth.
Valtteri Bottas, meanwhile, finished down in 19th position after he stopped on track when his Mercedes W09 suffered a hydraulic failure.
Charles Leclerc sprung a surprise by briefly leading the way before the front-runners improved and he finished in sixth, just seven-tenths of a second down on former karting rival Verstappen.
Renault slipped back to seventh and 10th respectively, with Carlos Sainz Jr. again in front of Nico Hulkenberg.
They were split by Toro Rosso’s Pierre Gasly and Sauber’s Marcus Ericsson, who backed up team-mate Leclerc to demonstrate the pace of the Ferrari-powered C37.
Force India missed out on the top 10, with Esteban Ocon heading home favourite Sergio Perez, while Romain Grosjean was 13th.
McLaren duo Stoffel Vandoorne and Fernando Alonso, who posted the first timed lap over halfway through the session, showed slightly improved performance in 14th and 15th, while Brendon Hartley was unable to replicate his FP2 form as he slipped to 16th.
Williams pair Sergey Sirotkin and Lance Stroll finished ahead of the stricken Bottas, while Kevin Magnussen’s woes continued as he finished at the back.
Haas' Magnussen completed just one installation lap due to an intercooler problem.
Qualifying is scheduled for 13:00 local time