Ferrari's Charles Leclerc edged Lewis Hamilton's Mercedes to set fastest time in a weather-affected second practice at the Italian Grand Prix.
Leclerc, fresh from his maiden win in Belgium, was 0.068 seconds quicker than Hamilton. Ferrari's Sebastian Vettel was third, 0.201secs off the pace.
The second Mercedes of Valtteri Bottas was fourth, from the Red Bulls of Max Verstappen and Alexander Albon.
Intermittent rain made competitiveness harder to read than usual.
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The changeable weather meant that the teams ran their sessions to different timetables, Ferrari and Red Bull cramming in their qualifying simulation laps early in the session before the first rain shower, Mercedes preferring to wait until it had passed.
That also meant an off-set in the later race-simulation preparation, on which Mercedes appeared to have an advantage but on which Ferrari may have been affected by a damper track for the start of their runs.
Nevertheless, the performance pattern of the cars appeared as expected - with Ferrari having an advantage on a single lap but Mercedes faster over a longer run.
That is exactly the pattern seen in Belgium, where Leclerc took pole by three-quarters of a second, but won the race with a charging Hamilton right on his tail.
Among the top six, there was a notable performance from Albon.
In only his second race for Red Bull following his promotion from Toro Rosso, he was a creditable 0.239secs slower than Verstappen, who will start this weekend from the back of the grid as a result of a penalty for using too many engines.
That is also the case for Toro Rosso's Pierre Gasly, who was seventh fastest, and McLaren's Lando Norris, who ended up 18th after missing the first half of the session while McLaren fixed an oil leak.
Behind Gasly, Renault's Daniel Ricciardo, Toro Rosso's Daniil Kvyat and the second Renault of Nico Hulkenberg completed the top 10.
There were a few spins and off-track moments, but no accidents, unlike the first session, when both Alfa Romeo's Kimi Raikkonen and Racing Point's Sergio Perez had heavy crashes.
"Not a massive amount different to the last race," said Hamilton afterwards. "They (Ferrari) are quite quick in a straight line. We are quite strong on race pace but perhaps a little closer potentially on single-lap pace so it looks like we have a fight."
Vettel added: "It was OK but we can still get more out of the car. The main thing is we got some decent laps, we know where the weaknesses are and that's what we try to work on."