The German led his Brazilian team mate Rubens Barrichello across the line by 14.5 seconds on an afternoon of sun and showers at Silverstone for his 60th career triumph and seventh victory in 10 races this year.
It was Ferrari’s fourth one-two finish of 2002 and Schumacher could secure the title in record time at the French Grand Prix in two weeks’ time.
Failing that, he looks certain to be crowned before his own adoring fans at Hockenheim on July 28.
Schumacher, whose only other victory in Britain came in 1998 a year before he crashed and broke his leg at Silverstone, now enjoys a 54-point lead over Barrichello.
The Brazilian set the fastest lap, a race record time of one minute 23.083, after going from the front row to the back of the field when his car stalled before the formation lap.
The German has 86 points, Barrichello 32, Colombian Juan Pablo Montoya 31 and Ralf Schumacher 30.
Montoya was third for Williams, again failing to translate his fourth successive pole position into victory but at least finishing after three straight retirements.
Canadian Jacques Villeneuve, the 1997 world champion with Williams and twice a winner at Silverstone, was fourth to end British American Racing’s nightmare position as the only team yet to score points this year.
In a double celebration for BAR, Villeneuve’s French team mate Olivier Panis was fifth, ahead of the Sauber driven by German Nick Heidfeld.
Apart from Ferrari, BAR were the only team with two cars in the points and they too clearly reaped the benefit of Bridgestone’s wet weather tyres.
The changeable weather, with intermittent showers of varying intensity, led to multiple pitstops and some chaotic scenes with drivers coming in together, fuel rigs failing and mechanics unprepared.
Montoya started unchallenged after Barrichello’s misfortune and led untroubled through the first corner with Schumacher in hot pursuit.
The Colombian held off the champion until the 15th lap, when Schumacher slipped past on the approach to Club corner and began to pull away.
Barrichello, meanwhile, was carving his way back up through the field and was second by the 19th of the 60 laps.
Results:
Race distance: 60 laps, 308.356 kms
1. Michael Schumacher (Germany) Ferrari one hour 31 minutes 45.015 seconds; 2. Rubens Barrichello (Brazil) Ferrari 1:31:59.593; 3. Juan Pablo Montoya (Colombia) Williams 1:32:16.676; 4. Jacques Villeneuve (Canada) BAR one lap behind; 5. Olivier Panis (France) BAR one lap; 6. Nick Heidfeld (Germany) Sauber one lap; 7. Giancarlo Fisichella (Italy) Jordan one lap; 8. Ralf Schumacher (Germany) Williams one lap; 9. Felipe Massa (Brazil) Sauber one lap; 10. David Coulthard (Britain) McLaren two laps; 11. Pedro de la Rosa (Spain) Jaguar two laps; 12. Jenson Button (Britain) Renault six laps.
Not classified (did not finish):
Takuma Sato (Japan) Jordan 50 laps completed; Kimi Raikkonen (Finland) McLaren 44; Jarno Trulli (Italy) Renault 29; Enrique Bernoldi (Brazil) Arrows 28; Eddie Irvine (Britain) Jaguar 23; Heinz-Harald Frentzen (Germany) Arrows 20; Mika Salo (Finland) Toyota 15; Mark Webber (Australia) Minardi 9; Allan McNish (Britain) Toyota 0.
Fastest lap:
Barrichello, lap 58, 1:23.083 (222.760 kph)—Reuters