"Every championship is special for different reasons, it's unforgettable every time and this day is no different. I'm world champion once again and now I want to go and party!" Rossi concluded.
“We have to give huge congratulations to Valentino because this year we've seen him work harder than ever, and when the level goes up he puts even more effort in and this means that we, too, have all had to work even harder to keep up with him!” added Brivio.
Rossi's nine titles are split four with Yamaha, three with Honda and two with Aprilia.
Fiat Yamaha has won the 2009 Teams' title while Yamaha is assured of the Constructers' crown providing M1 riders do not break the new engine limit rules.
The final round of the 2009 MotoGP season will be held at Valencia on November 8.