VALENCIA, Spain (Reuters) - Spanish rookie Marc Marquez held his nerve became the youngest MotoGP world champion at the age of 20 when he finished third in the final race of the season in Valencia on Sunday.
The Honda rider, who started from his ninth pole position of the year, played it safe by avoiding a thrilling tussle between defending champion Jorge Lorenzo and Dani Pedrosa, who went on to finish the race first and second.
Marquez secured the title with 334 championship points, four ahead of twice former winner and Yamaha rider Lorenzo, and 34 in front of Pedrosa.
He passed Freddie Spencer's 30-year-old record from when the American won his maiden crown at the age of 21, also on a Honda, pipping compatriot Kenny Roberts in the final race of the year at Imola in 1983.
"Congratulations Marc to you and the team! I couldn't be happier for you! Enjoy this moment!," the 51-year-old Spencer said on his Twitter feed.
The Catalan-born Marquez also became only the fourth rider in the 65-year history of Grand Prix racing to win world titles in three different categories, along with Mike Hailwood, Phil Read and Valentino Rossi.
"It was the longest race of the year for me," Marquez told Spanish broadcaster Telecinco with a grin from ear to ear.
"I was very nervous at the start. I know I had said I wasn't, but I was. Jorge started very well and I wasn't sure quite what to do.
"The first 10 laps were the worst with Jorge and Dani in front and the others right behind, but I settled into it after that.
"It has been a great year. This has arrived earlier than I expected. Maybe too early, but I want to thank everyone from my team and the fans."
Lorenzo, who had cranked up the pressure on Marquez by winning the last two races in Australia and Japan, flew off the grid to hit the front at the first bend with Spanish compatriot Pedrosa in second, and Marquez third.
Pedrosa and Lorenzo went on to delight the fans with a battle for first place with Marquez watching from third, as the two rivals in front of him swapped positions with breath-taking passes over the opening laps.
With 10 laps gone Marquez hit the front, cutting inside the bend as the front two came together and Pedrosa was forced wide, dropping down to fifth.
Race officials said they would investigate the incident on the MotoGP's official Twitter feed.
The 26-year-old Lorenzo muscled his way back to the front a lap later and the title rivals pulled away from the rest of the field, while Pedrosa recovered ground to pressure his Honda team mate in second.
Marquez appeared to let Pedrosa pass him with five laps remaining and cruised across the line, Lorenzo's third successive victory being too little, too late.
"It's been a great championship. To have two Spaniards fighting for the title at the end is something special," said Lorenzo, who became the first MotoGP rider to win at least eight races in a season and not take the title.
"Marc has been the deserved winner. We also deserved to win, having won so many races and had so many podiums, but for a rookie to win six and have so may podium finishes you cannot take anything away from him."
Marquez went over to where his fans were massed, waving red flags emblazoned with his number 93, climbed on a barrier and threw his gloves into the crowd as he punched the air before bowing to them all.
In Moto2, newly-crowned world champion Pol Espargaro crashed, leaving Spanish compatriot Nico Terol to win followed by Jordi Torres and Johann Zarco.
Another Spaniard, Maverick Vinales, was crowned world champion on a KTM in the Moto3 race, hitting the front on the final lap to finish ahead of Jonas Folger and Alex Rins who was runner-up in the championship.
Spaniard Luis Salom, who had led the rankings going into the final race, crashed out and limped home in 14th place.
Writing by Mark Elkington in Madrid, editing by Ed Osmond