Mark Webber kept Red Bull ahead in final Japanese Grand Prix practice at Suzuka, as his team-mate Sebastian Vettel ran into mechanical problems.

It was a commanding morning for Webber, who put himself on top during the early part of the session when everyone was on hard tyres.

He was deposed by an early medium-tyre run from Lotus’s Romain Grosjean, but once Webber was on the softer rubber as well, he burst clear with a 1m32.053s, 0.643s clear of the field.

Vettel had been second to Webber on hard tyres, 0.314s off his team-mate’s pace after what he admitted had been a scruffy lap.

That ended up being Vettel’s best run as a KERS problem then left him watching the final quarter of an hour from the pits.

Webber looked set to keep his six tenths advantage until late runs from the two Mercedes.

First Nico Rosberg got to within 0.302s of the Red Bull, then Lewis Hamilton put in a 1m32.187s after the flag to take second from his team-mate, 0.134s behind Webber.

Grosjean was pushed back to fourth, ahead of Ferrari duo Fernando Alonso and Felipe Massa.

Jenson Button took an encouraging seventh place for McLaren, with a tenth of the Ferraris.

Kimi Raikkonen, Vettel and Nico Hulkenberg completed the top 10.

Adrian Sutil provided the only crash of the session when he ran wide on the exit of Spoon and put his Force India into the barriers, sustaining relatively minor damage.