Valentino Rossi has won his seventh MotoGP title, one round early, by finishing third in a wet and wild Malaysian Grand Prix dominated by Casey Stoner.

The race was delayed when - after two days of dry practice and qualifying, and dry conditions for the 125 and 250cc races - rain began pouring down on the Sepang circuit 25 minutes before the planned MotoGP start.

Further drama followed when second on the grid Jorge Lorenzo - the only rider still able to deprive Fiat Yamaha team-mate Rossi of the title - was forced to start from the back of the field 'having failed to join his starting position on time'. Lorenzo's number one bike had refused to start in the pits, prompting him to switch to his spare machine.

At the other end of the grid, Rossi began the race from his seventh pole of the year and needing only fourth place to secure the title before Valencia - even if Lorenzo won the race.

The 21-lap main event began on a fully wet track, with rain still falling, and saw Rossi attempt to keep his advantage by out-braking perennial fast-starter Dani Pedrosa into turn one - a move that backfired when the Italian ran wide and was swallowed by the pack.

A fired-up Lorenzo exited the first turns in eleventh and had overtaken Rossi on his way to eighth by the end of the opening lap! Rossi crossed the line tenth, while up front Stoner had overtaken Pedrosa to lead the field, with Pedrosa's Repsol Honda team-mate Andrea Dovizioso third.

Ducati star Stoner stormed to a six-second lead over Pedrosa within four laps, by which time Lorenzo and Rossi had settled into seventh and eighth.

Lorenzo then overtook Suzuki's Loris Capirossi, a move mirrored by Rossi, but Nicky Hayden offered tougher resistance to the young Spaniard - who took five attempts to pass the Ducati rider.

The #99 gained fourth place from countryman Toni Elias on lap seven, but Rossi continued to follow his team-mate's every move up the order - then, having gained confidence in the conditions, calmly outbraked Lorenzo on lap eight.