Mark Webber topped the final practice session ahead of qualifying for the Belgian Grand Prix, although there was a brief scare for team-mate Sebastian Vettel when he ground to a halt in the pit entry during the session.
As was the case during both practice sessions yesterday, rain played a part in proceedings as a heavy shower hit the circuit towards the end of the hour-long session which prevented drivers from setting quick laps late on.
With the session starting damp, it took time for the drivers to start setting quick laps – with a number of different people taking their turn at the top of the times.
Webber posted the quickest time with a lap of 1min 46.106secs - which was easily the best time of the weekend – and ended up just over a tenth of a second clear of Lewis Hamilton in second place.
Webber's Red Bull team-mate Vettel ended the session with the third quickest time, but only after his session was brought to a premature conclusion when he ground to a halt on the entry to the pits with his car stuck in gear.
Vettel was pushed back to the garage by marshals before Red Bull was able to look into the issue, which the team linked to an air box problem that saw him told to cut the engine. While the engine was restarted in the garage, worsening conditions meant he didn't take to the circuit again.
Jenson Button was fourth quickest in the second McLaren, with Robert Kubica and Friday pace-setter Fernando Alonso rounding out the top six.
Elsewhere, Mercedes struggled down in 14th and 15th places with Michael Schumacher just ahead of Nico Rosberg. Schumacher was one of the few drivers who elected to go out on wet rubber towards the end of the session.
Of the newcomers, Jarno Trulli was quickest in 19th place but was more than two seconds behind Tonio Liuzzi's Force India. Encouragingly for Hispania Racing, Bruno Senna was second quickest but some six-tenths down on Trulli.