A near capacity British Grand Prix crowd were rewarded for braving some appalling weather at Donington Park by one of the most thrilling, unpredictable and action-packed races of the 2005 season so far - which ended with world champion Valentino Rossi taking a memorable victory after emerging from a frantic four-man lead group.

As many had feared, and some riders had hoped, after two days of dry action (with the exception of drizzle on Friday afternoon) a large band of rain moved into the midlands overnight, soaking the circuit from the early hours of Sunday onwards.

The rain continued on and off throughout the morning - producing a wet warm-up led by Suzuki's Kenny Roberts. The American - who led in the wet at Shanghai before mechanical problems - had qualified just 16th, but would hold a 0.254secs advantage over pole sitter Rossi by the end of the 20-minute session.

Movistar Honda's Marco Melandri - who would complete the front row alongside Rossi and Sete Gibernau - was third fastest in the warm-up, with Ducati's Carlos Checa a fraction behind in a top four covered by 0.351secs. Capirossi, Biaggi, Bayliss, Barros, Gibernau and Hayden completed a sliding top ten.

A brief lull in the rain would follow, but any hopes of a dry race ended when a sustained downpour forced the 125 race to be stopped and restarted - and by the time the 21 MotoGP stars took to the grid at 15.30 (to avoid a clash with the German F1 GP) the rain was falling heavier than ever - leaving standing water all around the sweeping 4km circuit.

This would be some challenge - which ultimately only half the field would finish - and just to add to the tension the start was aborted at the last moment when Nakano's Kawasaki died on the grid. Fortunately, after just one minute the bikes were restarted and sent out on a second warm-up lap, with the race distance being reduced by 1 lap to 29 as a result.

The second start went without a hitch, but as the red lights disappeared Rossi might have thought his M1 had selected reverse as he plummeted down to seventh, due to excessive wheelspin, by the time the field reached turn one.

Inheriting his position at the front was Gibernau, who led team-mate Melandri, a fast starting Troy Bayliss and Camel Honda team-mate Barros, Max Biaggi, Colin Edwards and then Rossi through hollywood and down the craner curves for the first time.

However, as the field threaded through the old hairpin, Biaggi became the first faller of the afternoon, the Roman sliding from his Repsol Honda before making a brief - but ultimately futile - attempt to continue.

Meanwhile, three men were on the move up front; Gibernau, Edwards and Rossi. Sete was setting a relentless pace to pull seconds out of the pursuing pack, while Edwards was soon ahead of the Camel Hondas and breathing down Melandri's neck for second.

But Rossi had other plans and the London based Italian would outbrake Bayliss, Barros and Edwards into the foggy esses for the first time although, in a sign of things to come, Barros quickly cut back past the world champion on the run down to the melbourne hairpin - then snatched second from Melandri into the final turn!

As the field crossed the line for the first time, Gibernau was already 2.4secs clear of the five man chasing pack - of Barros, Melandri, Rossi, Bayliss and Edwards - but all home eyes were on the man in seventh, with Brit Shane Byrne having used all his Donington knowledge to charge from 18th on the grid to the edge of the lead group!

Meanwhile, lurking just behind the Team Roberts rider were Suzuki team-mates Kenny Roberts and John Hopkins - who were also making impressive progress and would come into play later... By contrast, Repsol Honda started packing up early after US GP winner Nicky Hayden retired the second factory RCV following a final turn highside, from seventh, at the end of lap two.

Lap 3 would see Rossi rise to second and set his sights on Gibernau for the first time - and the #46 would be handed a bonus championship boost when second in the points Melandri fell at the final turn, the Italian sliding outwards towards fellow frontrunner Bayliss, whom he clipped - sending Troy ran wide onto the grass where the Australian fell into retirement at almost walking speed.

The Doctor was handed a further gift seconds later when race leader Gibernau, whom Rossi had began to catch, highsided from his blue Honda at turn one on lap 4 - the furious Catalan had almost saved the rear end slide before it pitched him over the bars for his third DNF of the year.

With his three nearest title rivals - Melandri, Biaggi and Gibernau - now out, and Barros now mounting a strong counter attack, Rossi could have been forgiven for backing off slightly and waiting to see how the race played out.

After all, there were still 25 laps to go and, while his 79-point championship lead could easily absorb a Donington DNF, it couldn't absorb a DNF combined with an injury - so the Italian had plenty to lose in trying to take on the combative Barros.

But Rossi simply doesn't think that way and even after a near highside at hollywood a lap later - which handed Barros the lead - Rossi remained right in the Brazilian's wake. However, the two Suzukis had now also joined the fight, with Roberts and Hopkins using their Bridgestone tyres to set the fastest laps of the race.

The GSV-R riders had passed Edwards on lap 3 and on lap 5 alone a charging Hopkins would overtake his team-mate, outbrake Rossi for second at the Melbourne hairpin - then seize the lead from Barros!

All the afternoon's main players were now in place and, by lap 6, Hopkins, Barros, Rossi, Roberts and Edwards held a seven-second lead over nearest rival Makoto Tamada. But while the contenders had now been named, one would soon fall victim to the treacherous conditions.

Hopkins led across the line for two laps before a near highside out of the final turn on lap 7 saw the 22-year-old lose drive and - with his rivals so close - drop straight to the tail end of the group.

But worse was to follow a lap later when, perhaps partly due to visor misting problems, the #21 ran wide at the high-speed Schwantz curve and fell from his Suzuki as it snaked for traction on the grass. The ever-determined Hopkins would remount and return to the pits for emergency repairs, before rejoining a race he would finish in 11th and last.

Hopkins's departure had handed the lead back to Barros, but four laps later (on lap 11) former world champion Roberts hit the front for the first time. However, the American would be credited with just one lap at the helm before Barros retaliated, but when Rossi also tried to demote the #10 he outbraked himself at the foggy esses - sending the current world champion back to the tail of the group.

It was at that point that Rossi showed just what he could do, the 26-year-old setting the fastest laps of the race to quickly claw back the 3-second gap to third placed team-mate Edwards - and on the following circuit Rossi carved passed the Texan at coppice, then immediately stole second from Roberts under braking for the esses.

But Barros was a different prospect and, despite persistent pressure from Rossi, the #4 would hold the lead from laps 12 to 21 - with the Italian, Roberts and Edwards never more than two-seconds from the Brazilian veteran.

With only Edwards able to enjoy breathing room behind, the atmosphere remained incredibly tense during those laps, especially with each rider running a different line to avoid the spray in front, while constant fish tailing from the rear wheels and frequent front-end tucks kept fans and riders on a knife edge.

Having battled so hard to stay in contention Rossi, unlike at Laguna Seca, clearly only had victory in mind - and the inevitable attempt for the lead would come at the end of lap 21, when he dived inside Barros at the Melbourne hairpin.

The way his Yamaha was twitching through the following corners left little doubt that Rossi's plan was to break away there and then, but even he must have been surprised at the pace of his exit - with whole seconds being gained at almost every turn!

With three laps to go Rossi was an amazing eight-seconds ahead - his advantage built in just five laps - but while Rossi concentrated on the still sizeable task of staying upright through the puddles, a battle was brewing for the final podium positions.

Barros had begun to pull away from Roberts in his attempts to stay with Rossi, but with two laps to go Roberts had reeled Alex back in and was now firmly in his wheel tracks - while Edwards, although not threatening, was still near enough to pounce on any mistakes.

As any MotoGP rider will say, overtaking Barros is no easy task and the Brazilian held firm right until the last half of the last lap - when Roberts put a gutsy inside move on the Estoril winner as they pitched into the coppice corner, prior to the back straight.

Barros did his best to rebuff the move, but as the pair accelerated side-by-side through the ever quickening corner it would be Roberts - frequently criticised for lacking fight - who triumphed.

The American then duly held on to claim his best result since his 2000 world championship season - and Suzuki's first podium finish since Rio 2002 - after crossing the line 3.169secs behind Rossi.

But the Italian had backed right off, and would receive the chequered flag for his seventh victory of the season playing an imaginary Violin after glancing back and gesturing 'where are they all?'

Meanwhile, Barros collected a well deserved third in his 250th GP start, while Edwards backed off in the closing stages to claim a safe fourth. Checa would end the event in a distant fifth for Ducati on a day when the Spaniard set the third fastest race lap, behind Rossi and Barros.

Checa and sixth placed Capirossi - like all the Bridgestone riders with the possible exception of Kawasaki - clearly had their race day hopes saved by the rain, but the Marlboro riders couldn't carve through the field as fast as the Suzukis and paid the price.

Tamada crossed the line 15secs behind Capirossi for a lonely seventh, the Konica Minolta Honda rider enjoying a 7secs advantage over Kawasaki's Alex Hofmann, while MotoGP rookies Toni Elias and Roberto Rolfo kept their heads to finish in front of Hopkins.

Joining Biaggi, Hayden, Melandri, Bayliss and Gibernau on the DNF list were Ruben Xaus, Shinya Nakano and WCM riders Franco Battaini and home hero James Ellison.

Ellison was spat from his machine at Coppice and countryman Byrne would exit in similar fashion - the disappointed Brit crashing out of sixth on lap 5 as he touched the brakes for the Melbourne hairpin.

In terms of the championship standings, Rossi's victory - combined with a zero points score for his main rivals - means that he is now a barely believable 104-points ahead of Melandri, while Edwards has overtaken both Gibernau and Biaggi to sit third, just one point from Marco.

British Grand Prix:

1. Rossi
2. Roberts
3. Barros
4. Edwards
5. Checa
6. Capirossi
7. Tamada
8. Hofmann
9. Elias
10. Rolfo
11. Hopkins