Mark Webber was fastest in the final practice session for the Turkish Grand Prix, the Australian resisting late challenges from Renault's Fernando Alonso and Red Bull teammate David Coulthard.

As has been the pattern this season, the title contenders appeared to work on preparations for Q3 in this session and carry heavier fuel loads, with Ferrari's Felipe Massa the best of the usual front-runners in fifth place, behind Williams driver Nico Rosberg.

Lewis Hamilton was the best of the McLarens in seventh, with championship leader Kimi Raikkonen 11th-fastest for Ferrari.

The session got off to a slow start as damp patches lingered on the circuit following a heavy shower earlier in the morning. After their installation laps, the drivers returned to the pits to let the circuit dry out fully, with no one setting a flying lap until Timo Glock (Toyota) ventured out after 20 minutes.

The German's time of 1:30.427 - just 1.6 seconds slower than his best dry lap yesterday - convinced the rest of the field that the circuit was ready, and a frantic period followed as drivers tried to make up for lost time on a track that was getting quicker with every lap.

Hamilton, Rosberg, Alonso, Nelson Piquet (Renault) and Raikkonen all headed the times within a ten minute period, before Massa hit the front with a 1:27.530.

As had been the case on Friday, it took the Ferraris several laps to get up to speed, with both Raikkonen and Massa setting their best times several laps into their stints, whereas their rivals had been on the pace immediately.

Massa remained on top for a quarter of an hour until Coulthard continued his promising Istanbul form by beating the Ferrari driver, lapping 0.190 seconds faster with eight minutes to go. The only man who could beat Coulthard's time was his teammate, as Webber beat the Scot by 0.3 seconds in the final two minutes.

Coulthard improved on his last run and closed the gap to 0.190 seconds, but the Red Bull duo were then split by Alonso, who beat Webber's time in the first sector but was 0.142 seconds adrift over the course of the lap.

A similar late improvement took Rosberg to fourth, ahead of Massa and Jarno Trulli (Toyota), with Hamilton, Glock, Jenson Button (Honda) and Piquet completing the top ten.

Raikkonen ran wide at Turn 1 on his last run and ended up 11th. His error was one of the few incidents of the session, along with spins by Kazuki Nakajima (Williams) at Turn 6 and Sebastien Bourdais (Toro Rosso) at Turn 10.