Motor sport:World champion Fernando Alonso put troubled McLaren on top in free practice for Ferrari's home Italian Grand Prix on Friday.
The Spaniard, whose team risk exclusion from the championship they currently lead after allegations that they benefited from leaked Ferrari technical information, lapped the Monza circuit in one minute 22.386 seconds.
His championship leading team mate Lewis Hamilton followed him on the afternoon timesheets with a lap 0.823 seconds slower.
Kimi Raikkonen had led Ferrari team mate Felipe Massa in a one-two in the opening session at the oldest and fastest circuit on the calendar.
The Finn, preparing for his first race in Italy as a Ferrari driver after replacing now-retired seven-times champion Michael Schumacher, clocked 1:22.446 seconds in the morning but was only eighth in the afternoon.
Hamilton, five points clear of double world champion team mate Fernando Alonso at the top of the standings, was third in the morning with the Spaniard fourth after losing time because of an engine misfire.
Massa, who led Raikkonen in a one-two in Turkey two weeks ago to revive his title hopes, is 10 points adrift of Alonso with five races remaining. Raikkonen is fourth and a point further back.
However the McLaren drivers could find their title challenge halted if a hearing in Paris next week finds against their team in the spy saga that has gripped the sport since July.
Williams's Nico Rosberg raised the Toyota-powered team's hopes with the fifth best lap in both sessions.
Italian Giancarlo Fisichella, hoping for a new contract with outgoing champions Renault, was seventh quickest in the morning and third in the second session.
BMW Sauber's Polish driver Robert Kubica, who finished third last year in a race won by Schumacher, clocked the fourth best time of the afternoon.
The Swiss-based team, third in the constructors' championship, are hoping to close the performance gap on the leaders this weekend.
The afternoon session was halted for nine minutes to allow Briton Anthony Davidson's stricken Super Aguri to be moved safely from the track.