Brazilian Rubens Barrichello reminded Ferrari of his talents on Friday with the fastest lap in a wet and windy first qualifying session for Sunday's Canadian Grand Prix.
His time of one minute 30.925 seconds bore no comparison with last year's pole of 1:12.836.
Schumacher was second quickest, a hefty 1.044 slower than his team mate, after skidding wide at the hairpin on a treacherous surface glistening like an ice rink.
"There was a lot of aquaplaning and therefore it was hard to do a time on just one flying lap," Schumacher said. "In any case, things went pretty well."
Both were fortunate to be among the early runners as conditions deteriorated, the cars pitching and sliding as walls of spray billowed out behind them.
Renault's Italian Jarno Trulli was one of the worst affected, lapping more than 10 seconds slower than Barrichello as he slithered around the circuit perched on an island in the St Lawrence Seaway.
"What can I say," Trulli said. "As I left the garage, it was as if a thunderstorm had just started ... things can only get better tomorrow."
SCATTERING SEAGULLS
Resting seagulls scattered as championship leader Kimi Raikkonen ventured out first under the single lap qualifying format, the Finn coaxing his car to a sixth best time of 1:35.373.
Colombian Juan Pablo Montoya, winner of the Monaco Grand Prix for Williams two weeks ago, tracked over the grass at turn eight and McLaren's David Coulthard did the same at turn three.
"There was no grip and I think we were all just aquaplaning and concentrating on getting the car back in one piece," Coulthard said.
Canadian Jacques Villeneuve, whose father Gilles won the race 25 years ago, spun his BAR full circle at the last corner before the finish straight and was fortunate to avoid hitting the wall.
The 1997 champion, who has not scored a point in his home race since his debut season in 1996, recovered to finish but was slowest of all with a time of 1:44.702.
"I guess I found the limit in the last corner but the crowd seemed to enjoy it," said the Canadian, who will start first in Saturday's decisive session.
The rain eased slightly towards the end of the session, introducing a surprise element with Briton Ralph Firman placing his Jordan in fourth place (1:34.759) while Minardi's Dutch driver Jos Verstappen was 11th quickest.
Both Minardis were faster than Ralf Schumacher's Williams and Briton Jenson Button, who was returning for BAR after missing the Monaco race when he crashed in practice.
Button was 14th fastest, a fraction slower than his compatriot Justin Wilson in a Minardi.