Sebastian Vettel topped the times ahead of Mark Webber as Red Bull dominated Friday afternoon's second free practice session for this weekend's Italian Grand Prix.
The defending triple world champion was fastest throughout and clocked a best lap time of one minute and 24.453 seconds at Monza, leaving the German six-tenths of a second clear of the field.
Australian Webber was second ahead of Finn Kimi Raikkonen and his Lotus team-mate, Frenchman Romain Grosjean, with Spaniard Fernando Alonso fifth for Ferrari and Briton Lewis Hamilton sixth for Mercedes.
Hamilton had been fastest in the morning's opening session ahead of Alonso but the pair were unable to mount a serious threat in the afternoon heat as the Red Bull duo delivered a stunning demonstration of consistent speed at the Autodromo Nazionale.
Hamilton's Mercedes team-mate German Nico Rosberg was seventh ahead of Brazilian Felipe Massa in the second Ferrari and the two improved McLarens of Briton Jenson Button and Mexican Sergio Perez.
On a hot late summer's afternoon in the former royal park north of Milan, the air temperature was 30 degrees Celsius (86 degrees Fahrenheit) and the track temperature 44 degrees, a combination that ensured hot tyres under a clear blue sky.
Defending champion Vettel's form was a blow to his rivals as he holds a clear lead in the drivers' standings with 197 points ahead of Alonso on 151 and Hamilton on 139.