His first World Championship race was in 2002 at Mugello, in the 125cc class. Since the following year he has competed regularly in the world championship level.
In 2003, he achieved two 9th places and finished 19th in the final standings. In the following year he improved and ended 13th in standings while his team-mate, Andrea Dovizioso, won the championship. In 2005 they both moved to 250cc, but were now riding different bikes.
Corsi had good first half of the year as he finished in the points in seven of the eight races. However, in the second half he finished in the points only once. He returned to smaller class for 2006. Two fourth places and other lesser placings gave him 12th spot in the championship. But as five riders ahead of him moved to 250cc class, his 2007 looked promising.
He won Turkish Grand Prix at Istanbul, but apart from that, achieved only one podium and finished in 6th place. For 2008 he received a factory spec Aprilia RSA 125 and he was a title favourite for the year. He ultimately lost out to the Derbi of Mike Di Meglio.
For 2009, it had been speculated that Corsi would ride for the Scot Honda team in 250's, but he continued in 125s with Aprilia.
In 2010, the Italian stepped up to the new intermediate Moto2 class, for Team JiR. He scored his first podium – and his team's first podium – in the class at the French round at Le Mans, moving into third place in the championship standings. He added another podium at Mugello, but a crash at the Sachsenring dented his championship hopes.
Source : Wikipedia.com