MONZA (Italy) - Two-time world champion Fernando Alonso topped the times for McLaren Mercedes-Benz in Saturday morning's final practice session ahead of the Italian Grand Prix.

At the end of a session extended by 20 minutes after Finn Kimi Raikkonen ploughed into the barriers in his Ferrari, Alonso was fastest ahead of his team-mate, championship-leading Briton Lewis Hamilton.

The Spaniard clocked a best time of one minute and 22.054 in the final two minutes of the session run in dry conditions under a blue sky - with an air temperature of 25 degrees Celsius and a track temperature of 32 degrees.

Hamilton was just one-tenth of a second slower behind him, and ahead of the Ferrari of Brazilian Felipe Massa and German Nick Heidfeld in a BMW Sauber.

Poland's Robert Kubica was fifth fastest in the second BMW and German Nico Rosberg sixth in a Williams.

The session was overshadowed however by the big accident that saw Raikkonen veer right and smash into the barriers at the Variante Ascari chicane after 24 minutes.

The right side of his car was severely damaged and the front right wheel almost broken off. Raikkonen walked away uninjured.

The Finn was approaching the Ascari chicane when his Ferrari appeared to suffer a mechanical failure and jerked violently to the right.

It hit the concrete barrier and slid at high speed along a strip of grass that lay between the gravel trap and the barrier before crashing heavily into the tyre wall.

Raikkonen climbed out unhurt, but the session was red-flagged while the car was collected and the tyre barrier repaired.

After the interruption, Hamilton and Alonso traded fastest laps until the Spaniard reeled off two quickest laps to top the times. --AFP