Ralf Schumacher produced a controlled drive at Sepang to add a fourth grand prix victory to his resume, and notch up the first Williams 1-2 finish since the Portuguese Grand Prix in 1996.

The German had to bide his time in a race-long battle with early leader Rubens Barrichello, but benefited when his single-stop strategy played out over the closing laps. His margin of victory was later extended when the Brazilian retired with engine failure, producing the historic 1-2 as Juan Montoya inherited second place.

Schumacher and Barrichello, combatants over a far shorter distance in Melbourne two weeks ago, should not have been the pace-setters, however, but were given the reins when front row starters Montoya and Michael Schumacher clashed at the first corner.

Although not having the devastating effect of the opening lap in Melbourne, the incident served to delay both pre-race favourites. Schumacher carved across in front of Montoya's Williams as soon as the lights went out, and held the inside line as long as he could on the long drag run to the Selangor S.

Montoya's prodigious BMW power had the Williams running neck-and-neck by the time the pair reached the first right-hander, however, but appeared to pinch Schumacher onto the inside kerb as they turned in. Schumacher, later claiming a touch of understeer, then ran off the painted surface, collecting Montoya just behind his front wheel and pushing the Colombian to the outside of the corner.

His wing broken off in the impact, Schumacher had to watch as the field streamed past his hobbled Ferrari, finally making it back to the pits trailing the pack. Montoya, meanwhile, rejoined in the midfield and promptly began to work his way back towards the front.

At the end of the opening lap, the Colombian was on the fringes of the top ten, but trailed leader Barrichello by some distance. The Brazilian was also beginning to eke out a gap to Schumacher Jr, the Williams clearly running a heavier fuel load than the Ferrari. The rest of the points-paying places at this point were occupied by the two McLarens - Kimi Raikkonen having got away ahead of team-mate David Coulthard - with Nick Heidfeld and Jenson Button in fifth and sixth, having moved up two places apiece as a result of the first corner incident.

The excitement didn't end there, however, for Montoya's comeback soon had him on the tail of Jarno Trulli and Mika Salo, with places changing between them over the next few laps. Jordan twins Takuma Sato and Giancarlo Fisichella were also running in close company, which became a little too close when the Japanese rookie ran into, and over, his Italian team-mate on lap two.

It appeared that Fisichella was forced to back off behind Allan McNish's Toyota, catching Sato slightly off guard as they rounded turn two. With nowhere to go at the speed he was travelling, the Japanese driver ended up using the other Jordan as a ramp, breaking front and rear wings of each car respectively. Both returned to the pits together, but Sato was able to rejoin sooner as Fisi's car underwent remedial surgery.

While Montoya was making progress back towards the points, Schumacher Sr was reeling in the tailenders. His pit-stop had dropped him behind the luckless Heinz-Harald Frentzen, who had his Arrows stall at the start for the second race running, and, once the German had been dealt with, the Minardis already had a head-start on the world champion, who ran 19th on lap five.

Thins between the two front row starters were soon to be evened up, however, as Montoya was assessed Formula One's first ''drive-through' penalty for his part in the incident. Accused of squeezing Schumacher onto the kerbs, the Colombian maintained his innocence all the way through his slow pass of the garages, before rejoining a far from chastened ninth.

Already out by this stage were Jarno Trulli and Olivier Panis. The Italian had been running well in seventh before Montoya caught him first time round, but slowed and pulled into the pits with obvious mechanical trouble. Panis touched the back of Pedro de la Rosa's Jaguar in the early going, before stopping out on track to complete a miserable weekend.

Four places separated Montoya from Schumacher by lap ten, but the leaders were already enjoying a comfortable advantage over their immediate pursuers. With Barrichello pulling out an ever-increasing gap over the leading Williams, both were also dropping the McLarens.

McLarens soon became McLaren, as Nick Heidfeld highlighted the first sign of trouble in the number three machine. Coulthard's luck evaporated altogether when both Button and Salo came past before the end of the same lap, and it wasn't long before the Scot notched up his second retirement of the season.

That was not before he played a part in fellow countryman McNish ceding seventh place to the charging Montoya, the Toyota carrying too much speed into the next corner after passing the stricken McLaren and running out of road. McNish rejoined, but Montoya was already homing in on his next target.

A series of fastest laps had the Colombian onto the tail of Salo's Toyota in a matter of minutes but, having passed the Finn, Montoya's charge was interrupted again when he had to make his first regulation pit call. He returned ahead of the Toyota and, with half the field also choosing to stop at the stage was back into the points in short order.

His quest for a podium place was then aided further by the second McLaren retirement of the weekend, Raikkonen's Mercedes engine letting go in dramatic fashion heading into the final corner. By now, though, Montoya's ultimate quarry was his team-mate, Schumacher Jr having taken advantage of Barrichello's first pit-stop to assume the lead.

Barrichello was short-filled at his stop, as Ferrari attempted to get him back out ahead of Raikkonen, who was one-stopping, but failed marginally, leaving the Brazilian behind the McLaren at the time of its demise. The incident did not appear to hinder Barrichello either, but he now trailed the leader by over twenty seconds - and Ralf was still turning in record laps.

The places were reversed when the Williams made its sole stop on lap 30, but Barrichello had little time to savour re-taking the advantage because his own schedule saw him pitting again just five tours later. Another five laps down the line and it was all over, however, the Ferrari pulling off trailing a plume of smoke and leaving a distraught Brazilian stranded at trackside.

Schumacher now enjoyed a massive gap back to his nearest pursuer, who turned out to be the surprising Button. The Renault driver was back to the sort of form that he last exhibited before being supplanted by Montoya at Williams, and was not about to let his replacement - now in third - have an easy ride to the podium.

Having pitted for a third time, including the penalty, Montoya was soon back on the Briton's tail, and the pair duelled over the course of a lap before superior BMW power told again. The order, however, now appeared set, with Schumacher Sr having dropped away from the front three courtesy of his own final pit call.

Joining the list of retirements at this point were Enrique Bernoldi's Arrows, which stopped on track and prompted a flurry of yellow flags, both Minardis, and Irvine's Jaguar, which had earlier run into the back of Alex Yoong's KL-backed car and required a new wing.

Despite the apparent gaps between the top six, the closing laps turned out to be anything but dull, as Button's maiden podium finish suddenly appeared to be in jeopardy. The Briton had pitted at the same time as the leader, and had enough fuel on board to prevent him having to slow down, but it was clear that Schumacher's Ferrari was suddenly catching him at a rate of knots.

Later to claim that the car was crabbing in left-handers, Button tried to offer resistance to the world champion, but it proved futile and Schumacher duly joined his brother and his biggest rival on the podium.

There were none of the expected recriminations, however, as the Ferrari driver and Montoya agreed on a racing incident. The only accusations now remain to be fired by the respective tyre companies as the typically tropical conditions took their control on rubber of all denominations.

Race Results:

1. Ralf Schumacher Germany Williams-BMW 56 laps 1hr 34mins 12.912secs 197.680kph
2. Juan Montoya Colombia Williams-BMW +39.700secs
3. Michael Schumacher Germany Ferrari-Ferrari +1min 01.795secs
4. Jenson Button Britain Renault-Renault +1min 09.767secs
5. Nick Heidfeld Germany Sauber-Petronas +1 lap
6. Felipe Massa Brazil Sauber-Petronas +1 lap

7. Allan McNish Britain Toyota-Toyota +1 lap
8. Jacques Villeneuve Canada BAR-Honda +1 lap
9. Takuma Sato Japan Jordan-Honda +2 laps
10. Pedro de la Rosa Spain Jaguar-Cosworth +2 laps

11. Heinz-Harald Frentzen Germany Arrows-Cosworth +2 laps
12. Mika Salo Finland Toyota-Toyota +3 laps
13. Giancarlo Fisichella Italy Jordan-Honda +3 laps

Rtd Rubens Barrichello Brazil Ferrari-Ferrari 39 laps completed
Rtd Mark Webber Australia Minardi-Asiatech 34 laps completed
Rtd Eddie Irvine Britain Jaguar-Cosworth 30 laps completed
Rtd Alex Yoong Malaysia Minardi-Asiatech 29 laps completed
Rtd Kimi Raikkonen Finland McLaren-Mercedes 24 laps completed

Rtd Enrique Bernoldi Brazil Arrows-Cosworth 20 laps completed
Rtd David Coulthard Britain McLaren-Mercedes 15 laps completed
Rtd Olivier Panis France BAR-Honda 9 laps completed
Rtd Jarno Trulli Italy Renault-Renault 9 laps completed