Billy Mackenzie may have graduated to the MX1 class this season, but his love affair with the Sugo circuit in Japan continued on Sunday - as the Scotsman stormed to his debut premier-class victory.

Mackenzie had won both previous MX2 events at Sugo, but his 2007 triumph made him the first and so far only British rider to have won an MX1 grand prix... and he did it despite being sent flying over the handlebars in race two.

The Kawasaki star had passed Mike Brown early in race one - then promptly disappeared - leaving the fast-starting American to fight with championship leader Josh Coppins. Brown faded to an eventual fifth late in the race, but Coppins found new problems in the shape of KTM team-mates Davide Philippaerts and Jonathan Barragan.

The kiwi managed to repel German GP winner Philippaerts, but Barragan proved a tougher opponent - and passed the factory Yamaha star for second with two laps to go.

The second race again saw Brown leading Mackenzie and Coppins in the early stages, before Mackenzie again began to dominate. However, 'Billy Mac' was later pitched spectacularly over the handlebars on a tabletop jump - while leading comfortably - handing the lead back to Brown. Mackenzie sprung to his feet and remounted, behind Brown and ahead of Coppins, but this time CAS Honda rider Brown didn't fade and hung on to take his first moto win of the season.

Despite his scare, and a broken helmet peak, second place for Mackenzie gave the rookie his first overall grand prix victory, ahead of Brown, while Coppins completed the podium in third. Josh now holds an enlarged 63 point championship lead over Suzuki's Kevin Strijbos, who - like team-mate Steve Ramon - was never a contender at the front on Sunday. Brown is now eighth in the standings, with Mackenzie eleventh.

In the MX2 class, Antonio Cairoli saw his unbeaten 2007 season end when reigning world champion Christophe Pourcel took a narrow victory over the Italian ace. The Kawasaki star won race one ahead of KTM's Tyla Rattray, while Cairoli was third after a fall.

Cairoli bounced back with an early lead in race two and, after repelling a determined Rattray attack, rode to the moto victory. Rattray fell from second, handing the position to Pourcel, who also fell - and was forced to pit to get his handlebars straightened. The Frenchman rejoined in fourth, but clawed back his first GP victory of the season by overtaking both Gareth Swanepoel and Tommy Searle by the chequered flag.

Despite the disappointment of seeing his perfect streak end, Cairoli holds a 64 point lead over Pourcel in the championship.