Max Verstappen led birthday boy Carlos Sainz by just 0.046s in Practice 1 at the Italian Grand Prix.
The reigning Formula 1 champion would set a 1m22.657s on the hard tyres, with many teams opting to use just one set for the whole hour due to the Alternate Tyre Allocation of just 11 sets for the weekend instead of the usual 13.
Sainz would improve on his second run to finish P2 just behind the Red Bull on the same compound as Ferrari ran their ultra-low downforce rear wings from last year.
Their respective teammates, Sergio Perez and Charles Leclerc, sat third and fourth with three-tenths covering the four drivers.
George Russell took fifth for Mercedes, ahead of Fernando Alonso on medium tyres in sixth for Aston Martin.
Lando Norris was the highest-placed soft compound runner in seventh, followed by the newly re-signed Lewis Hamilton in eighth.
Yuki Tsunoda sat ninth with Alex Albon surviving a brief trip through the gravel at the Ascari chicane en route to P10 in the Williams.
Oscar Piastri finished 11th ahead of Logan Sargeant and Liam Lawson, again replacing the injured Daniel Ricciardo, in 13th for AlphaTauri.
Pierre Gasly was the highest-placed Alpine in 14th. Valtteri Bottas claimed 15th in an eventful session for Alfa Romeo.
Both the Finn and teammate Zhou Guanyu failed to get out of the pits at the start due to anti-stall issues before Bottas complained of the rear stalling with their low downforce package.
Eventually, the issues were resolved, though Zhou would finish the slowest of the 20 drivers.
Nico Hulkenberg claimed 16th, followed by Esteban Ocon. F2 champion Felipe Drugovich was 18th in the Aston Martin, as Kevin Magnussen and Zhou completed the timesheet.