By Alan Baldwin
MONZA, Italy (Reuters) - Nico Rosberg led Mercedes team mate Lewis Hamilton in another show of strength by the dominant Formula One champions in first practice for the Italian Grand Prix on Friday.
The German lapped the fastest track on the calendar with a best time of one minute 22.959 seconds, 0.203 quicker than championship leader Hamilton.
Ferrari were best of the rest at their home track with Finland's Kimi Raikkonen third on the timesheets but more than a second off Rosberg's pace while team mate Sebastian Vettel was fourth.
The Italian team have used the last of their season's engine 'tokens' for a power boost at the track outside Milan after ceding second place in the championship to Red Bull.
Hamilton leads Rosberg by nine points going into the last European race of the season but can hope to extend that on Sunday.
The Briton is chasing his third successive Italian Grand Prix win, a feat that has not been achieved since the late Argentine Juan Manuel Fangio in the 1950s, and 50th career victory.
Rosberg, winner in Belgium last weekend, set his best lap on the soft tyres as did Hamilton, who was one of several drivers to have off-track excursions as they probed the limits.
McLaren's Fernando Alonso provided the only real incident of the session when he crawled back to the pits with a gearbox problem five minutes from the end.
Mexican Sergio Perez was fifth fastest for Force India, ahead of Romain Grosjean's Ferrari-powered Haas and the Williams of Valtteri Bottas.
Dutch teenager Max Verstappen, whose aggressive defending against Raikkonen at Spa last weekend is still the talk of the paddock, was eighth for Red Bull.
Verstappen and McLaren's Jenson Button lapped with a version of the 'halo' head protection device attached to the cockpits of their cars.
(Editing by Ed Osmond)