Lewis Hamilton set the early pace as track action got underway at Monza for the Italian Grand Prix.
Hamilton’s time of 1:25.565 was 0.035s quicker than Ferrari’s Fernando Alonso.
Nico Rosberg was third, with Sebastian Vettel in fourth and the longer wheelbase Lotus of Kimi Raikkonen in fifth.
The opening half an hour was fairly quiet, with only Marussia reserve driver Rodolfo Gonzalez circulating at a comparatively sedate pace.
He was later joined by more esteemed rivals as the temperature crept towards 30 degrees on a sunny morning in Monza.
Sergio Perez set the benchmark time of 1:26.007 although reigning champion Vettel soon eclipsed that with a 1:25.914. Vettel’s stay at the top lasted for a few minutes until Alonso gave the home crowd a cheer by lowering Vettel’s time by 0.051s.
Hamilton, who had earlier run wide at the Roggia chicane, then went quicker, but only by a further 0.035s in his Mercedes. Alonso tried to beat his former team-mate but ran wide exiting Parabolica and was subsequently fractions slower.
The Rettifilio chicane was the corner causing most grief for the drivers as Pastor Maldonado, Romain Grosjean, Nico Hulkenberg and James Calado all had to take to the run-off.
Maldonado also had an excursion across the gravel at Ascari after approaching the corner sideways; team-mate Valtteri Bottas suffered a similar fate in his Williams.
Nico Hulkenberg endured a difficult session as gearbox issues restricted him to a lowly eighteenth place.
James Calado completed his first official practice session for Force India and the Brit, driving in place of Adrian Sutil, finished the session in seventeenth position.
The only other drama came during the closing moments when Felipe Massa narrowly ran the red light at the end of the pit lane and had to stop his Ferrari, before walking back to the garage.
It was a fairly close session, with the top 14 cars separated by just 0.884s.