MOTEGI - Frenchman Johann Zarco became the Moto2 world champion Friday ahead of the Japanese Grand Prix, after his closest rival Tito Rabat pulled out with an injury. Zarco, on a Kalex, had a 78-point lead against defending champion Tito Rabat and needed to come out of Sunday's race with a 75-point advantage to guarantee his season victory.

In the end he didn't need to race. Spaniard Rabat had to abandon the Japanese race during the first free practice session Friday morning due to pains from a broken left radius, sustained in a training crash on Monday.

Throughout this season, Zarco has dominated the field, having collected 284 points in the 14 races so far. Of those races, Zarco has managed 12 podium finishes: six wins, five second places and one third place. The Frenchman said he pushed himself to take risks this season, but also managed to apply his experience to win races.

"I wanted to enjoy (claiming) the world championship," he said. "I did it this year. It's perfect. I want to keep going like this," he said, vowing to defend his title. Rabat congratulated Zarco for securing the championship and putting up an impressive performance throughout the season.

"He's ridden a faultless season and will be a worthy champion," Rabat said. Meanwhile, Rabat said his team will assess the status of the injury next week before deciding whether he will participate in the Australian Grand Prix the following weekend. "There was little pain, but I just didn't have the power in the injured arm needed to cope with the hard braking areas here at Motegi," Rabat said. "The championship is gone and second place is not worth the risk of crashing again and making the injury worse," he said.