McLaren-Honda protege Lando Norris proved the master of wet conditions in the official test day at Monza ahead of this weekend's Formula 3 European Championship round.
Norris, the 2016 McLaren Autosport BRDC Award winner, took his Carlin Dallara-Volkswagen to the fastest time in both sessions.
The track was at its grippiest during the first half of the afternoon session, and every driver set his quickest time during this period.
Norris's best was 0.221 seconds quicker than Honda-backed Tadasuke Makino in the lead Hitech Grand Prix Dallara-Mercedes.
Makino was also second fastest to Norris in the morning session, the Japanese F3 Championship graduate finishing 0.391s behind the reigning Formula Renault Eurocup champion.
Prema Powerteam duo Maximilian Gunther and Callum Ilott ended the day third and fourth respectively, Gunther taking the same position in the morning session, in which Ilott was fifth.
Jake Dennis was fifth for Carlin, ahead of Hitech GP's Ralf Aron, while the top 10 was completed by Jehan Daruvala, Pedro Piquet, Ferdinand Habsburg and Guan Yu Zhou.
Championship leader Joel Eriksson, who as at Silverstone had never driven at Monza before, was 16th but did not do many laps when the track was at its least slippery - the Swede was fourth in the morning session.
The afternoon session was interrupted by two red flags, one for a crash by David Beckmann and another to recover the car of Nikita Mazepin.