Marc Marquez has become the youngest MotoGP champion as a third-place finish at the season-ending Valencia Grand Prix secured him the 2013 world title in his rookie year.
Jorge Lorenzo won the race but Marquez, 20, only had to finish fourth to become the first debut-season title-winner since American Kenny Roberts in 1978.
Dani Pedrosa was second, but only Lorenzo could deny Marquez.
"This is a dream that comes true," he said. "I cannot explain what I feel."
The result meant Marquez finished just four points ahead of Lorenzo in the standings, the smallest points margin since 1992.
Confirmation of the title win for Marquez sparked wild celebrations throughout the 104,000-strong crowd as the young Spanish rider wrote his name into the history books.
In a stunning first year at this level, Marquez became the youngest winner of a premier class race with victory at the Circuit of the Americas in April, won the most races in a single season as a rookie with six and is the youngest to win four races back-to-back.
"I didn't expect to fight for the championship this season," Marquez told BBC Sport. "Jorge Lorenzo did a great job but thanks to my team."
Lorenzo, 26, said: "Marquez has been a deserving champion. Today is his day."
The title fight had been taken to the wire after Marquez had been disqualified from the Australian Grand Prix, - a race Lorenzo won before then taking victory in the penultimate race in Japan.
Marquez had started Sunday's race on pole but was overtaken by 2012 champion Lorenzo at the first corner.
MotoGP: Title is a dream come true - Marc Marquez
Conscious of the need to avoid unnecessary risks, Marquez showed maturity not to get involved in a tussle with Lorenzo at the front.
Instead, his team-mate Pedrosa battled with his fellow Spaniard Lorenzo before contact between the two with 21 laps to go saw the former drop down the field.
Marquez then briefly fought his way into the front but Lorenzo again battled back to take the lead.
With the gap between the front three and rest of the pack increasing, Marquez appeared to sense he had done enough to secure the title as he rode safely to third place, with Pedrosa having fought his way back up to second.
Seven-times world champion Valentino Rossi finished fourth, while Briton Cal Crutchlow crashed out.
Valencia Grand Prix results:
1. Jorge Lorenzo (Spa) Yamaha 46'10.302
2. Dani Pedrosa (Spa) Repsol Honda 46'14.236
3. Marc Marquez (Spa) Repsol Honda 46'17.659
4. Valentino Rossi (Ita) Yamaha 46'20.881
5. Alvaro Bautista (Spa) Honda Gresini 46'25.267
6. Stefan Bradl (Ger) LCR Honda 46'34.701
7. Bradley Smith (GB) Tech 3 Yamaha 46'39.345
8. Nicky Hayden (US) Ducati 46'50.195
9. Andrea Dovizioso (Ita) Ducati 47'03.498
10. Michele Pirro (Ita) Ducati Test Team 47'13.285