WHILE HIS rivals were consulting their computerised weather forecasts, Michael Schumacher looked at the sky. They saw a prediction of clear weather. He saw clouds and sniffed rain. Two hours later, his Ferrari splashed across the finish line of the Monaco Grand Prix almost a minute ahead of its nearest rival.

Schumacher's racing brain is most keenly activated by wet weather and yesterday's race provided further proof of his strategic brilliance. The reward was his - and Ferrari's - first win of the season, giving him the lead in the drivers' championship after five of the 17 races.

As a chilly wind rocked the yachts in the barb our, Rubens Barrichello brought the Stewart Ford into second place for the team's first championship points in their debut season, a fine result after starting from 10th on the grid.

After yet another race of incident and attrition around the principality, Eddie Irvine's third place in the other Ferrari provided the extra points to propel his team into the lead of the constructors' championship, ahead of Williams Renault.

The race's outcome was entirely shaped by the decisions made by the drivers and their team managers in the 30 minutes before the start, when spits of rain appeared to carry the threat of something worse.

With Heinz Harald Frentzen on pole position and Jacques Villeneuve starting in third position, just behind Schumacher, the Williams team trusted the computerised forecast of clearer weather and left both cars on slick dry weather tyres.

The gamble resembled the one made by the same team at Monaco 14 years ago, when they won their most recent victory at the circuit by sending Keke Rosberg to the start line on slick tyres in greasy conditions. While the Finn then streaked to victory on a drying track, yesterday's consequence was precisely the opposite.

While Frentzen and Villeneuve slithered towards the first corner, Schumacher reaped the rewards of his last minute decision to switch from his race car, set up for dry weather, to his spare chassis, which had been prepared for wet conditions and was fitted with a set of grooved rain tyres. A new high downforce wing was hastily bolted on while the car sat on the grid.

Six seconds ahead at the end of the first lap, he continued to open the gap as the rain intensified. Behind him, as the field swarmed chaotically through the twisting streets, the Williams Renaults had failed even to meet the secondary challenges.

The Jordans of Giancarlo Fisichella and Ralf Schumacher took swift advantage of their plight, holding second and third places while Frentzen and Villeneuve fell back to seventh and eighth, behind the fast rising Barrichello, the Sauber Ferrari of Johnny Herbert, and the Prost Honda of Olivier Panis.

Realising their catastrophic mistake, the Williams drivers made swift pit stops to change to grooved wet weather tyres. Villeneuve was first in, at the end of lap three, followed two laps later by Frentzen.

But Villeneuve, leading the championship at the start of the day, damaged his rear suspension against a guard rail and gave up alter 17 laps. His German team mate fumbled around until lap 40, when he drove into the barrier at the chicane.

McLaren took their meteorological advice from the same source, hedged their bets by starting Mika Hakkinen on slicks and David Coulthard on wets, and tared no better. When Coulthard spun at the entrance to the chicane on the second lap, crashing into the rail and putting himself out, he caused such confusion that Hakkinen, arriving several seconds later, ran into the back of a Benetton and eliminated himself.

The two Arrows cars had no better fortune. Pedro Diniz was already at a permanent stand still after spinning at Portier when, at the other end of the tunnel, Damon Hill tripped over the consequences of the Coulthard incident and broke his rear suspension against the back of Irvine's Ferrari, coasting to a halt just beyond the chicane.

By the fifth lap, Barrichello had overtaken both Jordans. Herbert retired from fifth place after crashing at Sainte Devote on the ninth lap, while Ralf Schumacher ended up in the barriers at Casino Square two laps later, leaving Panis to launch a long and ultimately successful campaign for fourth place, which he took from the fading Fisichella just after half distance.

The conditions, which raised the average lap time by more than 30 seconds, meant that the race was halted after the maximum permitted duration of two hours. Ferrari jubilation was exceeded by the celebrations among the Stewart team, who owed their first significant success not just to the quality of their Bridgestone rain tyres but to the wet weather prowess of Barrichello.