Daijiro Katoh claimed his first world crown in sensational style at Sepang today when he took victory in the 250cc Malaysian Grand Prix by a massive 15.6secs, to give him an uncatchable 34 point lead with one round to go.

The win caps a virtually faultless season for the Japanese star that has seen his stand on the top step of the podium 10 times - and sets the scene perfectly for his expected move into the newly named MotoGP class next year, with the Gresini team, on a two stroke NSR.

All eyes this weekend had been on Katoh as the Honda hero dominated qualifying to give him the perfect platform from which to wrap up the title. Such has been Katoh's speed that coming into the race he held a 1sec advantage over second placed starter Fonsi Nieto - with sole remaining title rival Harada back in sixth.

Katoh's cause was helped further by his teammate Emilio Alzamora popping the second of the Telefonica sponsored machines into third on the grid, while Aprilia privateer Robby Rolfo completed the front row.

As the red lights disappeared after a short delay Katoh kept his advantage, while Harada made a strong surge through from the second row of the grid to push Alzamora wide for second, with Fonsi Nieto settling into fourth, as the field negotiated the tight right left first chicane.

Lap 3 of 20 and Katoh's lead was already up to 2.4secs, while local hero Shahrol Yuzy crashed out of a promising fifth place on his Petronas Yamaha, while six placed Robby Rolfo also slide out of contention.

By lap 5 it was clear that only a rare mishap could rob Katoh of race - and championship - victory as his lead grew exponentially to 5.6secs over the three-way battle for second between Harada, Alzamora and Nieto, with McWilliams leading the fight for fifth some three seconds further back down the road.

Any thoughts that Katoh's claim that 'victory was the only way to take the title' was just posturing, given his huge points lead, disappeared as he pushed the #74 machine onto new lap records and a 9secs lead by lap 9 of 20.

The sister Telefonica Honda of Alzamora was fairing less well though, and having pressured Harada admirably since the start, the Spaniard lost the front of his #7 machine and slid into the Sepang gravel for another retirement, leaving Nieto to inherit a potential podium place, with Locatelli now ahead of McWilliams in fourth.

Lap 13 and Locatelli was the man to watch, the reigning 125cc champ now just 0.5secs behind Nieto, with second placed Harada just 1.5secs in front of the two on the #31 MS Aprilia.

Over the next few laps the trio were unable to either pull away from the rider behind - or catch the man in front - while all the time Katoh continued almost effortlessly towards the World Championship, holding a 15secs lead over Harada after 16 laps.

Onto the last lap and Katoh brought his Honda home over 15secs clear of Harada, with Nieto taking a well deserved third ahead of Locatelli, while Marco Melandri, injured after falling and tangling with Katoh in Motegi, rode bravely to eleventh on the factory Aprilia.

Katoh's Gresini crew intercepted their star rider halfway around his slowing down lap where he was duly mobbed and presented with a world championship celebrating T-Shirt, before collecting a huge Japanese flag and returning to the Sepang pitlane where the celebrations continued.

Full results to follow...

1. Katoh
2. Harada +15.618secs
3. Nieto +16.510secs
4. Locatelli +19.579secs
5. McWilliams +32.663secs
6. Battaini +45.819secs
7. Matsudo +46.048secs
8. Hofmann +46.520secs