Hiroshi Aoyama has been crowned the last ever 250cc world champion after both he and title rival Marco Simoncelli made mistakes in Sunday's Valencia title decider.

Aoyama was the first to stumble, spearing off-track after being squeezed under braking at turn one while battling in the lead group on lap ten of 27.

The Japanese plowed slowly through the gravel for what seemed like an age before rejoining in eleventh - the lowest position he could afford to finish in if Simoncelli won the race.

And Simoncelli was leading at the time of Aoyama's accident, but the pressure on the Japanese was eased when he claimed tenth place a few laps later - then was handed ninth when Mike di Meglio fell from fifth with seven laps to go.

But that all became academic when Simoncelli crashed out of the lead on lap 21. After becoming crossed up on the exit of turn one, the Metis Gilera rider lost the front at turn two and slid into retirement, instantly confirming Aoyama as champion.

Hector Barbera, who led the early race laps before being passed by Simoncelli, inherited the lead after Simoncelli's downfall and rode to his third grand prix win of the year by 3.663sec from Alvaro Bautista - and in doing so snatched second in the final standings from Simoncelli.

Aoyama crossed the finish line in seventh to be crowned champion by 22 points. Hiroshi celebrated by standing on the footpegs and clenching his fists as he crossed the line being mobbed by friends and fans on the slowdown lap.

A beaming Aoyama was then given a t-shirt with the words '250cc - last but not least!' Aoyama's team-mate Raffaele de Rosa completed the podium.

"I wanted to win this race and I was pushing and pushing - then at one moment I pushed too much!" smiled Aoyama. "It was like motocross when I went off the track and I was so far back. I recovered some positions and at the end I saw Simoncelli crash. Today is not the best for me as a race, but for the championship it is fantastic!"

Sunday's race was the 716th in the 250GP class, which has been included as part of the grand prix world championship series since 1949. The new Moto2 World Championship will replace 250GP from 2010.

Aoyama, Simoncelli, Barbera and Bautista will all move up to MotoGP next season.

Alex Debon, who had qualified on pole, was unable to start the race due to pain from a suspected broken rib - sustained just moments after setting his best lap at the end of qualifying.

Race results - Valencia:

1. Barbera (Aprilia)
2. Bautista (Aprilia) +3.663sec
3. de Rosa (Honda) +5.665sec
4. Luthi (Aprilia) +5.680sec
5. Wilairot (Honda) +13.601sec
6. Abraham (Aprilia) +13.697sec
7. H. Aoyama (Honda) +27.438sec
8. Baldolini (Aprilia) +35.097sec
9. Locatelli (Gilera) +35.866sec
10. Tomizawa (Honda) +40.176sec