Sergio Perez led Charles Leclerc and Max Verstappen during the first and only Friday practice session for the Brazilian Grand Prix.
His best effort was just 0.004s quicker than Ferrari's Charles Leclerc and 0.008s faster than teammate Verstappen.
The Mexican set his quickset lap midway through the session when both Red Bull's switched to the Soft-compound tyre, having initially set the pace on the Hard.
Leclerc set his fastest lap in the closing stages of the session along with Carlos Sainz in fourth, beating Lewis Hamilton and George Russell who rounded out the top six.
Traffic was an issue during some laps around the short, 2.6-mile circuit, as Charles Leclerc found out when he attempted to pass Stroll preparing for a hot lap early on.
The Ferrari driver nearly ran into the back of the Aston Martin, having to slam on the brakes before exclaiming "what is Stroll doing?" over the team radio.
Hamilton struggles with rear-end grip
Despite finishing the session fifth quickest, Hamilton was 0.187s off the pace set by Perez.
Speaking to his engineer Peter Bonnington, the Mercedes driver said "It's just floating around" in reference to the grip levels of his W13, having set times a time on the Medium that was good enough for 17th quickest.
He later went out onto the Softs with Russell at the end of the session, and initially went third quickest before getting bumped by Leclerc and Sainz.
Sebastian Vettel was P7 after a late improvement followed by Mick Schumacher in P8, with Valtteri Bottas and Pierre Gasly rounding out the top 10.
Both McLaren drivers also struggled for grip, with Lando Norris ending the session in P15 and Daniel Ricciardo in P20.
Result Free practice 1 - Brazilian
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