Sebastian Vettel streaked clear in final practice for the Chinese Grand Prix to finish almost half a second quicker than his Ferrari team-mate Kimi Raikkonen, with the Finn a further three-tenths quicker than third placed Valtteri Bottas.
Vettel's 1:33.018 was therefore more than seven-tenths up on what Mercedes could achieve, although it's unlikely that gap will be carried through to qualifying which is expected to be a much closer affair between the top three teams.
Red Bull's Max Verstappen was fourth, 0.951s down on the leader and ahead of the second Mercedes of Lewis Hamilton.
The second Red Bull of Daniel Ricciardo completed just four laps as his mechanics worked furiously to get his car out on track following a late gearbox inspection. However once out, the Australian suffered what appeared to be an engine failure. He finished way down in 15th.
Hamilton's session wasn't the smoothest as he span at Turn 10 having caught the wet astroturf and on a later lap looked set to go quicker before losing time in the final sector.
Kevin Magnussen continued to star for Haas as he finished up sixth fastest ahead of the Force India pair, Renault's Carlos Sainz and a surprise P10 for Sergey Sirotkin's Williams.
Nico Hulkenberg was P11 with McLaren's Fernando Alonso just 0.010 behind, whilst Stoffel Vandoorne was 13th, but experienced telemetry issues during the session.
Romain Grosjean was last and suffered from overheating brakes which caight fire at one point.
