Lewis Hamilton, with a 1m 22.600s, bested teammate Valtteri Bottas by just 0.048 seconds with the red-marked soft tyre, but such was the Briton and his team’s superiority that even his lap on the slower medium-compound rubber would’ve been enough to have him lead the session.
Behind the silver-clad pair was Max Verstappen and Pierre Gasly, but the Red Bull Racing teammates were 0.8 seconds behind the leading duo.
The team also ended the day with engine concerns after Gasly reported a lack of power from his Honda motor in the final minutes of afternoon practice.
Sebastian Vettel finished fifth for Ferrari, 0.873 seconds behind 2018 title rival Hamilton, but few believed the pace was representative given the German made an unusually small improvement between the morning and afternoon sessions, leading some to suggest the team was hiding its true pace ahead of qualifying.
Kimi Raikkonen was strong on his Alfa Romeo debut, splitting Vettel from Renault teammates Nico Hulkenberg and Daniel Ricciardo, the triumvirate around a second off Hamilton’s pace.
Renault endured mixed fortunes throughout the day. Hulkenberg spent more than an hour of his morning session with his car on jacks in the garage with an electronics issue, while new teammate Ricciardo lost almost 30 minutes of his afternoon to a technical problem before taking to the track, though both ended up in the mix at the head of the midfield as expected by the end of the day.
Charles Leclerc followed in ninth in the second Ferrari after spinning his car late in the afternoon session, and Haas driver Romain Grosjean rounded out the top 10.
It was a positive day for those anticipating another season of close battles in the midfield, with just a single second separating all drivers bar the leading Mercedes pair and quartet anchored to the bottom of the timesheet.
Thai driver Alex Albon had a debut to forget with Toro Rosso, leading that group of four outlying drivers at the back of the field after a scrappy two sessions, including a crash early in the day.
He spun his car into the turn-two barriers in the morning session, causing enough damage to the front and rear of his car to trigger a red flag, and though he made it to the end of the second session in one piece, it was similarly fraught, including by an off-track moment at turn 15. He ended the day in 17th place ahead of fellow rookie Lando Norris in the McLaren.
Williams duo George Russell and Robert Kubica ended the day at the very back of the field and substantially slower than the rest. Russell’s best effort was 3.8 seconds off Hamilton’s benchmark and 1.7 seconds off Norris immediately ahead of him.
Highlighting the team’s woes is that its best time of the day was almost a second slower than its best time of the same session last season despite most cars lapping more than a second quicker than they did in 2018.