SEPANG -- Spain's Daniel Pedrosa won the 125cc world championship with two races of the season remaining after victory in the Malaysian Grand Prix on Sunday.

The Honda rider, who turned 18 last month, crossed the line more than two seconds ahead of Finland's Mika Kallio in second and compatriot Jorge Lorenzo in third for his fifth race win of the season.

That gave Pedrosa his first world title as he took an unassailable 64-point lead in the standings over Italian Stefano Perugini, who retired from the race on the second lap.

Pedrosa capitalised on a superb start to take the lead on the first corner and dominate all the way to the finish with a time of 43 minutes 7.647 seconds.

"I don't know how to explain my feeling now," said Pedrosa.

"I just want to say thank you to my team and my family for helping me. I still cannot believe what I have achieved today -- maybe tomorrow."

Perugini's determination to make up for starting ninth on the grid saw him pushing to fourth halfway through the first lap until his forced retirement.

When Casey Stoner crashed out in the 12th lap, Pedrosa took advantage of the competition between the five riders in the chasing pack -- Lorenzo, Kallio, Thomas Luthi, Alex De Angeles and Masao Azuma -- to push further ahead for the win.