Mercedes driver Valtteri Bottas headed Ferrari’s Sebastian Vettel by just 0.027 seconds in second practice at the Chinese Grand Prix.
Max Verstappen’s Red Bull was third fastest, 0.221secs off the pace despite running wide at the final corner.
Lewis Hamilton’s Mercedes was fourth, 0.707secs off, while Renault’s Nico Hulkenberg and McLaren’s Carlos Sainz made it five teams in the top six.
Ferrari’s Charles Leclerc was seventh after problems on his quick laps.
Leclerc split the McLarens, with British rookie Lando Norris eighth, ahead of Renault’s Daniel Ricciardo and Red Bull’s Pierre Gasly.
Vettel’s 0.801secs advantage over his team-mate was exactly what the German needed after the Bahrain Grand Prix, where Leclerc dominated and was on course for a maiden victory before suffering engine problems late in the race.
Leclerc’s performance in Bahrain raised questions about Ferrari’s policy of favouring Vettel in marginal calls at the start of the season.
But team boss Mattia Binotto on Friday reiterated that Vettel remained the team’s priority, saying: “If there is any 50-50 situation where we need to take a decision, the advantage would have been given to Sebastian simply because Sebastian has got most of the experience with the team in F1.”
Leclerc aborted his first quick lap on the qualifying simulation runs and when he did finally try again after a number of slow laps he was not able to approach Vettel’s pace.
Leclerc also ran into problems later in the session – he was unable to do his race-simulation run because of a problem with the cooling system.
It is the third consecutive race in which the engine at Ferrari has caused a concern of one kind or another.
Before Bahrain, Ferrari had to run their engine at a lower performance level in the first race in Australia because of unspecified problems.
Mercedes felt they were on the back foot after Vettel headed the first practice session, but Bottas was able to usurp the German at the top of the times in the second session, when teams come close to simulating qualifying conditions.
And Bottas also appeared to have a slight performance advantage in the race runs later in the session.
However, both Mercedes drivers had pretty much identical spins early in the session, when rounding the interconnected Turns One and Two just after exiting the pits.