Toyota's Timo Glock was fastest in Saturday's rain-hit final practice for Sunday's Italian Grand Prix.
The German lapped Formula One's fastest circuit in one minute 35.464 seconds, his best lap coming before the downpour intensified.
Compatriot Sebastian Vettel was second on the timesheets, 0.665 slower in a Toro Rosso.
The times meant little, with cars lapping through plumes of spray as the rain fell steadily, although further wet weather later in the afternoon could spring a few surprises in qualifying.
McLaren's championship leader Lewis Hamilton, two points ahead of Ferrari's Felipe Massa with five races remaining, and team mate Heikki Kovalainen recorded the slowest times of the session.
Hamilton sat out most of the session, venturing out onto the track only in the final 10 minutes and with all the drivers remaining in the garages. His best time was 10.861 seconds slower than Glock's.
Ferrari's world champion Kimi Raikkonen, with his contract now extended to 2010, attempted only three laps and was 18th on the timesheets.
(Reporting by Alan Baldwin, editing by Clare Lovell)