Alvaro Bautista put a forgettable start to the 2008 season behind him with a dominate 250cc victory at Estoril on Sunday, as two of his title rivals suffered scares.

The Spaniard, who suffered a mechanical failure while leading on the last lap of his home Jerez race and was hit from behind by Marco Simoncelli - bringing them both down - blasted past pole sitter Simoncelli along the back straight during the opening lap, then rode into the distance.

Mapfre Aprilia rider Bautista, sixth at the Qatar season-opener but a former Estoril winner in both 125 and 250, eventually won round three by an untouchable 7.050secs over Simoncelli, while Jerez winner Mika Kallio mounted a late charge to draw alongside Simoncelli's Gilera on the run to the flag.

But when Simoncelli made a last-gasp change of direction to try and shake off the Finn, the two made contact, allowing Simoncelli to confirm second position - and his first 250GP podium - by a slim 0.013secs over the furious KTM rider.

The fight for fourth between Mattia Pasini, Hiroshi Aoyama and Yuki Takahashi was just as close, with championship leader Pasini falling after a collision with Aoyama - for which the polite Japanese later apologised - but Pasini soon had much greater worries.

After remounting, the Italian suffered a huge scare when he arrived at the end of the back straight without a front brake, which had been damaged in the earlier fall. The inevitable accident fortunately left Pasini unhurt, but his Polaris World Aprilia flipped high into the air before coming to a rest.

Kallio now leads the world championship by 12 points over Pasini, with Bautista up to fifth.

Race results - Estoril:

1. Bautista (Aprilia)

2. Simoncelli (Gilera) +7.050secs

3. Kallio (KTM) +7.063secs

4. Luthi (Aprilia) +12.998secs

5. Aoyama (KTM) +14.666secs

6. Takahashi (Honda) +18.498secs

7. Simon (KTM) +26.812secs

8. Barbera (Aprilia) +28.012secs

9. Faubel (Aprilia) +28.288secs

10. Pesek (Aprilia) +36.966secs

15. Laverty (Aprilia) +1min 21.363secs