Davide Valsecchi scored his fourth GP2 victory of the season at Monza on Sunday to take a 25-point lead into the final round in Singapore.
DAMS racer Valsecchi made a perfect start from third on the reversed-grid to dominate from lights-to-flag. He won by 0.4 seconds over Racing Engineering's Fabio Leimer.
Jolyon Palmer completed the podium for iSport, holding off team-mate Marcus Ericsson at Rettifilo by bouncing across the sleeping policemen.
Ericsson tumbled to seventh on the last lap after a fantastic side-by-side scrap with poleman Stefano Coletti through the Ascari chicane. Johnny Cecotto Jr and Max Chilton both passed the Swede too on the exit of the chicane, finishing fifth and sixth respectively.
Valsecchi extends his championship lead over Luiz Razia, who could only finish 16th after starting 25th due to a five-place grid penalty after his collision with Leimer on Saturday.
Lotus duo James Calado and Esteban Gutierrez kissed goodbye to their title hopes at Monza. Calado was 14th, while Gutierrez crashed out at the Parabolica on lap three, having collided with Cecotto and Luca Filippi on the opening lap.
Saturday's winner Filippi had to settle for fastest lap, after being forced to pit due to wing and tyre damage.
Results - 21 laps: Pos Driver Team Time/Gap 1. Davide Valsecchi DAMS 33m06.731s 2. Fabio Leimer Racing Engineering + 0.444s 3. Jolyon Palmer iSport + 7.873s 4. Stefano Coletti Rapax + 10.787s 5. Johnny Cecotto Jr Addax + 10.953s 6. Max Chilton Carlin + 11.418s 7. Marcus Ericsson iSport + 11.606s 8. Julian Leal Trident + 12.661s 9. Stephane Richelmi Trident + 13.383s 10. Giedo van der Garde Caterham + 14.540s 11. Sergio Canamasas Lazarus + 15.013s 12. Rio Haryanto Carlin + 15.711s 13. Rene Binder Lazarus + 15.934s 14. James Calado Lotus + 16.667s 15. Nathanael Berthon Racing Engineering + 20.179s 16. Luiz Razia Arden + 20.484s 17. Simon Trummer Arden + 25.436s 18. Ricardo Teixeira Rapax + 29.051s 19. Jake Rosenzweig Addax + 30.292s 20. Rodolfo Gonzalez Caterham + 34.034s 21. Felipe Nasr DAMS + 1m14.092s 22. Luca Filippi Coloni + 1m26.253s Retirements: Esteban Gutierrez Lotus 1 lap Nigel Melker Ocean 1 lap Fabio Onidi Coloni 1 lap Victor Guerin Ocean 1 lap