Kimi Raikkonen's title hopes have all but vanished after he retired from the lead of the German Grand Prix, handing victory to rival Fernando Alonso.
GERMAN GRAND PRIX RESULT
1 F Alonso (Renault)
2 JP Montoya (McLaren)
3 J Button (BAR)
4 G Fisichella (Renault)
5 M Schumacher (Ferrari)
6 R Schumacher (Toyota)
7 D Coulthard (Red Bull)
8 F Massa (Sauber)
The McLaren driver led from the start and had the race under control when he suffered hydraulics failure on lap 35.
Alonso's Renault now has a daunting 36-point lead with seven races to go.
Juan Pablo Montoya gave McLaren scant consolation by finishing second after starting from the back of the grid, with BAR's Jenson Button taking third.
Button, who started second, was passed by Alonso and Michael Schumacher's Ferrari at the start and the world champion held on ahead of the Englishman until after the first pit stops.
But Schumacher's grid position was the result of him choosing soft tyres in an attempt to provide extra grip, and these began to wear at the rear.
That allowed Button to close, and he passed the Ferrari on lap 45 in an impressive move down the inside of the hairpin at Turn 4.
Button had to pit for fuel at the end of the next lap, but he made up enough ground to be ahead when Schumacher emerged from the pits after his final stop on lap 49.
Schumacher's fading grip allowed Renault driver Giancarlo Fisichella and Toyota's Ralf Schumacher to close up on the Ferrari.
Raikkonen led from the start, but reliability problems struck again
Fisichella passed Michael Schumacher into Turn 4 on the last lap, but Schumacher was able to fend off his younger brother and hold on to finish fifth.
Red Bull driver David Coulthard and Sauber's Felipe Massa took the final points positions.
Raikkonen was in total control of the race, and streaked away into a comfortable lead after fending off a brief challenge from Alonso on the run to the first corner.
With Alonso in an equally comfortable second place, Raikkonen was on course to close on the Spaniard in the championship before his car ground to a halt. He left the track without speaking to the media.
Montoya's progress from the back of the field was the highlight of the race.
His pace underlined that McLaren have the fastest car in F1, but the team are throwing away Raikkonen's title chances through poor reliability.
Montoya was up to 11th after a brilliant first lap, and passed Toyota's Ralf Schumacher and Red Bull's Christian Klien to move up to ninth for the rest of the first stint.
A late first pit stop for fuel leapfrogged the McLaren up to fifth, whereupon he set about reducing the gap to Schumacher and Button ahead of him.
Lapping much faster than them, he made it a three-car battle for third place well before their second stops.
He stopped several laps later than both, and comfortably made up the time he needed to rejoin well ahead of Button to crown a superb drive.
Montoya was too far behind to do anything about Alonso ahead of him.
German Grand Prix result:
1 Fernando Alonso (Spa) Renault one hour 26 minutes 28.599 seconds
2 Juan Pablo Montoya (Col) McLaren-Mercedes +22.569secs
3 Jenson Button (GB) BAR-Honda 24.422
4 Giancarlo Fisichella (Ita) Renault 50.587
5 Michael Schumacher (Ger) Ferrari 51.690
6 Ralf Schumacher (Ger) Toyota 52.242
7 David Coulthard (GB) Red Bull-Cosworth 52.700
8 Felipe Massa (Brz) Sauber-Petronas 56.570
9 Christian Klien (Aut) Red Bull-Cosworth 1:09.818
10 Rubens Barrichello (Brz) Ferrari 1 lap
11 Nick Heidfeld (Ger) Williams-BMW 1 lap
12 Takuma Sato (Jpn) BAR-Honda 1 lap
13 Christijan Albers (Neds) Minardi-Cosworth 2 laps
14 Jarno Trulli (Ita) Toyota 3 laps
15 Jacques Villeneuve (Can) Sauber-Petronas 3 laps
16 Narain Karthikeyan (Ind) Jordan-Toyota 3 laps
17 Tiago Monteiro (Por) Jordan-Toyota 3 laps
18 Robert Doornbos (Ned) Minardi-Cosworth 4 laps
NC Mark Webber (Aus) Williams-BMW 12 laps
R Kimi Raikkonen (Fin) McLaren-Mercedes 32 laps
(Key: R=retired, NC=not classified)
Fastest lap: Raikkonen, one minute 14.873 seconds, lap 24.