Lewis Hamilton topped the opening practice session for the Brazilian Grand Prix, lapping the Autódromo José Carlos Pace in One minute, 11.895 seconds, just under a tenth of a second faster than Max Verstappen.
The Brit, sporting a special Senna-inspired helmet for this weekend, was two spots ahead of team mate and championship rival Nico Rosberg who was third fastest.
Felipe Massa was eighth fastest in what is the first session of his final home Grand Prix, while the Ferrari duo Sebastian Vettel and Kimi Raikkonen rounded out the top 10, despite a late spin for the German.
Romain Grosjean was 15th fastest for Haas, reportedly testing new brake material following a spate of failures.
Sirotkin's session ended earlier than expected due to a technical problem.
Bahrain International Circuit - Winter testing