Eight seconds behind Nieto, Barbera was in a 'safe' third - 9secs ahead of Ui and Perugini, while championship leader Pedrosa had his hands full defending sixth from Kallio, Luthi, Talmacsi and de Angelis.
Into the closing stages and Jenkner had responded to Nieto's earlier assault, pegging his advantage at an almost constant 10secs, while Barbera was now a further 15secs behind the Spaniard – indicating that the top three would remain unchanged unless anyone could be caught out by the treacherous conditions.
But having been so close so many times before, Jenkner wasn't going to let this chance slip through his grasp and duly rode confidently to a dominating first GP victory by 11.1secs at the flag, with Nieto claiming a solid second ahead of Aspar team-mate, and podium first-timer, Hector Barbera.
Championship leader Pedrosa took a lonely eighth, but will at least take heart from Cecchinello finishing out of the points in 16th - the Italian losing second in the championship to Jenkner as a result.
Full results to follow...
6. de Angelis