McLaren's Kimi Raikkonen produced a stupendous lap to take pole position for the San Marino Grand Prix from Renault's Fernando Alonso.
1 K Raikkonen (McLaren)
2 F Alonso (Renault)
3 J Button (BAR)
4 M Webber (Williams)
5 J Trulli (Toyota)
6 T Sato (BAR)
7 A Wurz (McLaren)
8 F Massa (Sauber)
Raikkonen, who was only 0.003 seconds ahead in first qualifying, produced a combined time of two minutes 42.880secs to extend his advantage to 0.561secs.
Michael Schumacher, who was third fastest after first qualifying, ran off the track and will start 14th.
BAR's Jenson Button moved up two places to third, with David Coulthard 15th.
Button supplanted Williams driver Mark Webber on the inside of the second row with a lap that was the third fastest of the day behind Raikkonen and Alonso.
Schumacher was chasing Button's time when he made an error braking for the Rivazza corner and slid off into the gravel trap.
He managed to regain the track but will now face a struggle to do well in a race that he really needed to win to get his title challenge back on track.
Schumacher is 24 points behind Alonso after a disastrous start to the season by his Ferrari team.
Raikkonen now believes he is in a strong position to take McLaren's first win of 2005.
"We ran quite a bit of fuel and I was happy with the car, straight out of the first corner it was working well," Raikkonen said.
"I got a bit sideways in the last corner but that didn't cost too much time so I am very happy.
"I don't know what the others are doing for the race but I think we are in a strong position."
Alonso said: "The gap to Kimi is quite big, and we saw yesterday that the performance of our cars was very close.
Schumacher will start 14th after a terrible error on his lap
"Given that the balance of my car has not changed since yesterday, and it is still stable and easy to drive, I hope that the difference between us is down to the strategy."
Jarno Trulli had to settle for his first grid slot outside the top three this season with fifth fastest time, ahead of Button's team-mate Takuma Sato.
The Japanese made up three places with a Sunday lap beaten only by Button, Alonso and Raikkonen.
McLaren's Alexander Wurz, standing in for the injured Juan Pablo Montoya, was seventh, with Felipe Massa of Sauber, Webber's team-mate Nick Heidfeld and the fastest Ferrari of Rubens Barrichello rounding out the top 10.
Australian Grand Prix winner Giancarlo Fisichella, Alonso's team-mate, failed to make amends for a poor lap on Saturday and lines up 13th.
Full qualifying line-up for San Marino Grand Prix:
1 K Raikkonen (Fin) McLaren two minutes 42.880 seconds
2 F Alonso (Spa) Renault 2:43.441
3 J Button (GB) BAR 2:44.105
4 M Webber (Aus) Williams 2:44.511
5 J Trulli (Ita) Toyota 2:44.518
6 T Sato (Jpn) BAR 2:44.658
7 A Wurz (Aut) McLaren 2:44.689
8 F Massa (Brz) Sauber 2:44.930
9 N Heidfeld (Ger) Williams 2:45.196
10 R Barrichello (Brz) Ferrari 2:45.243
11 R Schumacher (Ger) Toyota 2:45.416
12 J Villeneuve (Can) Sauber 2:46.259
13 G Fisichella (Ita) Renault 2:46.710
14 M Schumacher (Ger) Ferrari 2:47.244
15 D Coulthard (GB) Red Bull 2:48.070
16 V Liuzzi (Ita) Red Bull 2:48.155
17 N Karthikeyan (Ind) Jordan 2:52.099
18 T Monteiro (Por) Jordan 2:54.252
19 P Friesacher (Aut) Minardi 2:57.048
20 C Albers (Ned) Minardi 1:25.921 (accident in second qualifying)