Max Verstappen was left frustrated as he went off track twice in a first practice session dominated by home favourites Ferrari.
Charles Leclerc took charge of the session and it never seemed likely that it would end with his name not at the top of the timesheets. And he did exactly that, with a best lap one-tenth quicker than nearest challenger George Russell.
Carlos Sainz was third quickest to give the locals something else to cheer. Ferrari have brought upgrades this weekend, at one of their home circuits, and rivals Red Bull and McLaren expect the Italians to make a step forward.
As for the championship leaders, they could only manage fourth and fifth quickest. Sergio Perez got the better of team-mate Verstappen, who twice ended up off the tarmac as he tried to shave milliseconds off his lap times.
On the second occasion, he understeered off track and into the gravel. It was a mistake which clearly irked the Dutchman, who pounded his steering wheel in frustration as he made his way back onto the circuit.
Inside the driver call which upset Red Bull and changed the course of F1 historyHe was far from the only one who found the gravel in what turned out to be a messy session overall. Lewis Hamilton had a spin and was lucky to avoid hitting the barrier with his Mercedes.
Aussie duo Daniel Ricciardo and Oscar Piastri both took a trip through the gravel at Rivazza. And Sainz had to bail out of the Variante Alta chicane and take a trip across the grass, fearing he was not going to make the apex.
There was only one stoppage, though, as Alex Albon brought out the red flags. He did not lose control of his Williams, but lost power and was forced to pull over on the grass, leading to the session being briefly stopped.
The team said after the session that the car had completely lost power when he went over a kerb. Team principal James Vowles confirmed that shortly after the end of the session and said the team would investigate the problem and hoped to fix it before FP2.
Lando Norris won two weeks ago in Miami and came into this weekend brimming with confidence at a venue he loves. He and McLaren team-mate Piastri may have been holding something in reserve as they went eighth and ninth quickest respectively.