Ralf Schumacher roared to pole position at the Canadian Grand Prix in Montreal as Kimi Raikkonen made a mistake which could cost him the lead in the championship.
The German took his second top spot in succession - and third of his career -spearheading a one-two with Juan Pablo Montoya as the Williams-BMW duo revelled on the Circuit Gilles Villeneuve which had finally dried out after a day of rain.
Schumacher took pole by almost 0.4seconds from Montoya, victorious in the last race in Monaco, with Ferrari's Michael Schumacher forced to settle for third.
But the five-time world champion's hopes of taking the lead in the title chase for the first time this season were boosted when Raikkonen made a total hash of his qualifying and ended up last.
Ferrari ace Schumacher trails Raikkonen by just four points, heading into Sunday's race - the eighth round of the 16-race season - looking for a sixth victory on the circuit which is situated on an island in the St Lawrence Seaway.
Schumacher finished more than half-a-second slower than his brother, with Fernando Alonso fourth - while Rubens Barrichello was fifth as the Ferraris were unable to maintain the superiority they enjoyed in the wet.
David Coulthard's hopes of forcing his way back into title contention with victory on Sunday suffered a setback after another disappointing qualifying display as he finished 11th fastest.
The 32-year-old Scot, who trails team-mate Raikkonen by 23 points, had admitted beforehand he needed to improve his displays over the single lap but paid for a slight error at the last chicane.
But his disappointment was nothing compared to Raikkonen's after he went too wide at a chicane and slid across the grass to ram backwards into a tyre barrier.
The Finn briefly kept the car. But it then cut out, and he will start from last place on the grid for the second time in four races.
The last time he was in the same position - in Spain - he smashed into the back of Antonio Pizzonia's Jaguar on the grid and failed to finish on the podium for the only time this season.
Jenson Button, perhaps feeling some effects from his crash in Monaco two weeks ago, produced his worst qualifying performance of the season, finishing back in 17th place in his BAR-Honda.
The 23-year-old Brit was more than half-a-second slower than Canadian team-mate Jacques Villeneuve, who finished in 14th spot - having had the disadvantage of going out first on a track which finally dried out after being hit by rain for more than a day.
Justin Wilson finished one place further back than fellow Brit Button in 18th, while fellow Minardi driver Jos Verstappen will line up on the grid one row nearer the front on Sunday.
The duo's boss Paul Stoddart, embroiled in a row over finances with his rival team chiefs, could finally concentrate on what was happening on the track as he warmly congratulated both his drivers after their qualifying efforts.
Jordan's Ralph Firman was unable to repeat his heroics in the wet in first qualifying when he was fourth-fastest as he finished 19th in the dry, having nearly lost it at the very first corner, and will have championship leader - for now - Raikkonen for company on Sunday.
"That was a surprise," said the pole-sitter.
"We came here thinking we could be competitive but we weren't expecting a great result for the team. The car was perfect and thanks for the team for that.