Formula One: Hamilton on top as Rosberg's gears fail him

MONZA, Italy - Lewis Hamilton took full advantage of gearbox problems that hit Mercedes team-mate Nico Rosberg on Saturday to top the times in the third and final practice session for Sunday's Italian Grand Prix.

On a bright, warm and sunny morning at the old Autodromo Nazionale, Hamilton took a while to rise through the times before establishing himself as the quickest man on both the medium and harder tyres with a best lap in 1min 25.519sec.

Rosberg, who leads Hamilton by 29 points with seven races remaining in their almost private duel for the drivers' championship, finished up without a competitive time.

He was placed 22nd after a session in which, ironically, Hamilton was relying on his data from Friday practice for his set-up.

For Hamilton, it was a major boost after he had missed an hour of Friday's second practice session with electrical sensor problems that prevented his car from starting.

Hamilton was 0.412 seconds faster than nearest rival and two time champion Spaniard Fernando Alonso who gave the home Ferrari fans much to cheer with his unexpected speed and verve.

Fast-rising Finn Valtteri Bottas was third quickest for Williams, endorsing the impression that he and his team are likely to be one of the major threats to the dominant Merecedes outfit.

His Williams team-mate Brazilian Felipe Massa was fourth ahead of Briton Jenson Button of McLaren, defending four time champion German Sebastian Vettel of Red Bull, Finn Kimi Raikkonen in the second Ferrari and Russian Daniil Kvyat of Toro Rosso.

Australian Daniel Ricciardo, winner of the last two races for Red Bull and three of the last six, was ninth ahead of German Nico Hulkenberg of Force India.

Kvyat, who had his sixth engine of the season installed overnight, will face a 10-place grid penalty for exceeding the limit of five.