In what has become a rare sight in 2025, Hamilton topped the session with a 1m20.117s to finish 0.169s ahead of his teammate, sending the Monza crowd into raptures.

Under warm skies and with track evolution building slowly, Hamilton set his fastest time with four minutes remaining, pipping Leclerc, who had also recorded his best lap late in the session. Both drivers used soft tyres, which took time to reach their optimum window.

Max Verstappen had initially set the pace on mediums, with a 1m20.692s keeping him atop the timesheets for much of the hour.

But once several drivers switched to softs, the times tumbled, leaving the Red Bull driver fourth behind the Williams of Carlos Sainz.

Sainz had shown pace on the harder compounds too, sitting second for much of the session on hards before improving on softs. The Spaniard will be buoyant by the performance at a circuit where Williams has traditionally run strongly.

The session was largely uneventful, aside from a brief red flag after Racing Bulls rookie Isack Hadjar scattered gravel across the track following an off at Ascari.

The brief pause caused a scare for Leclerc, who was investigated for overtaking a Sauber under the red flag but was later cleared of any wrongdoing by the stewards.

Several other drivers, including Fernando Alonso, also had minor excursions at the chicanes, while others tested track limits by running through Monza’s various escape roads.

George Russell triggered a virtual safety car in the final minute after stopping with a hydraulic issue. The delay came shortly after a moment with Hamilton, when Russell moved aside to let him through at the second chicane before bailing into the escape road to avoid two other cars on flying laps.

The incident drew the attention of stewards, who are investigating whether Russell correctly rejoined the track. He ended the session eighth, while teammate Kimi Antonelli was fifth.

McLaren’s Lando Norris could only manage sixth, his fastest lap coming on mediums after aborting his attempt on softs. Rookie Alex Dunne filled in for Oscar Piastri for his second FP1 outing of the year, but the Irishman finished down in 16th.

Rounding out the top 10 were Alex Albon in seventh, Alonso in ninth and Hadjar in tenth.

Action resumes at Monza with FP2 at 5pm local time (1am AEST).