On 25 August 2009

On 25 August 2009, Lorenzo ended speculation surrounding a possible move to Honda or Ducati by signing a contract to race with Yamaha in the 2010 MotoGP Championship.^[17] Ducati reputedly offered him a 15 million dollar contract to take Nicky Hayden's position.
Lorenzo broke two bones in his hand in a pocket bike crash pre-season, therefore missing most of the pre-season testing. He fought through the field to finish second to Rossi in the season opener in Qatar, whilst still not fully fit.^[18] After Rossi broke his leg in a crash at Mugello, Lorenzo became the title favourite, with a 47-point lead after four wins in the first six rounds. Victory at Assen made him only the seventh rider ever to win in 3 classes at this prestigious circuit.^[19]
During a break between the Italian and British rounds of the championship, Lorenzo rode a Yamaha in a parade lap around the world famous Snaefell Mountain Course at the Isle of Man TT. He rode alongside former World Champion Ángel Nieto, later describing the experience as 'amazing'.^[20]
At the conclusion of the Senior TT, Lorenzo then took part of the garlanding ceremony, in which he bestowed garlands on third placed Bruce Anstey, second placed Ryan Farquhar and winner Ian Hutchinson, rounding off Hutchinson's historical five race wins at the 2010 TT meeting.^[21]Despite nearest rival DaniPedrosa making up ground in the latter stage of the season, Lorenzo was still in control with five races remaining. Pedrosa, the only man who could still overtake Lorenzo in the standings, then suffered a broken collarbone during practice, causing him to miss the next two races and virtually guaranteeing Lorenzo would become champion. On 10 October, Lorenzo clinched the title with a third place finish at the Malaysian Grand Prix behind Rossi and Andrea Dovizioso.^[22]