Monza was soaked by rain last night, and then again during the Formula 3 practice session earlier Friday morning. This meant that any representative times were hard to come by, with the only runs on slick tyres coming at the end of the session.
Leclerc was the fastest out of these final runs, with the Ferrari driver 0.306s faster than Carlos Sainz Jr in the McLaren. Sainz did spin on the outside of the Ascari chicane earlier in the session, but escaped without punishment.
Lando Norris was third fastest, however the British rookie struggled to make it round the first chicane throughout the session. He was another of the late slick runners, with McLaren hoping to collect as much data as they could in the closing minutes of the session.
Hamilton was fourth, with Red Bull rookie Alex Albon completing the top five. Daniil Kvyat was sixth, with the Russian showing great pace in changeable conditions once again after his podium in Germany.
Max Verstappen will be starting from the back of the grid this weekend alongside Norris, after both drivers have fitted new engines. Verstappen struggled to heat the tyres on his slick runs, and the Dutchman ended up down in seventh place.
Sebastian Vettel was next up in eighth place, with the Ferrari driver suspected to be running on high fuel on the end of the session. His best lap was 2.602s off his teammate's lap, with is definitely not representative of the German's pace at the Scuderia's home race.
Valtteri Bottas was ninth, with the Finn compromising his attempt at a chart-topping time with a spin at the first chicane.
Pierre Gasly rounded out the top ten, with the recently demoted Toro Rosso driver not being able to find the pace of his teammate Kvyat.
Antonio Giovinazzi did not re-emerge from the garage in the closing stages, as the Italian was another victim of the first chicane. He had a very slow speed spin on the intermediate tyres.
His teammate, Kimi Raikkonen, was last on the timesheets as he brought out the first red flag of the session. The Finn ran into the gravel at the Parabolica, just touching the wall in his Alfa Romeo.