The Aruba.it rider, who regularly rides at the Misano World Circuit in his test role for the manufacturer, set a 1m31.909s to top the timesheet on Friday morning.
He led from Marini, just one-tenth slower, who was confirmed on Thursday to be staying with VR46 for 2024, with Pramac’s Jorge Martin in third.
Championship leader Francesco Bagnaia, who escaped serious injury in a crash at last weekend’s Catalan GP, looked sore as he put in an early stint on his factory Ducati.
The reigning world champion was left with severe bruising after a massive highside in Sunday’s race before he was hit by Brad Binder’s KTM.
After an initial six-lap run, he took a break before going back out and ended the session in 20th with a 1m32.599s.
Fabio Di Giannantonio set an early benchmark on his Gresini Ducati, leading with a 1m35.889s, before Martin went quicker by 0.3s.
Pirro put in the first sub 1m35s time soon after, with a 1m34.507s, before a bruised Marco Bezzecchi, who was caught up in last weekend’s Turn 1 crash at Barcelona, went quickest with a 1m33.987s.
The VR46 rider was wiped out by Enea Bastianini, who sits out this weekend’s round, and suffered an injured left hand for which he is receiving thrice-daily physiotherapy.
The Aprilia pair, who claimed an historic 1-2 for the Noale factory last Sunday, then went fastest, with winner Aleix Espargaro ahead of Maverick Vinales.
Source: Autosport