Meanwhile, Biaggi was clawing his way back up the order after his dreadful start – holding sixth behind Capirossi by lap four and lapping faster than anyone. His rise through the pack continued unchecked until he came upon Bayliss, now third, who refused to budge.
Clearly being held up, Biaggi finally forced his way past the #12 through a right-left flick on lap 10, paving the way clear for him to attack the fellow RCVs of Gibernau (2secs ahead) and Rossi (a further 1.1secs).
However, disaster struck less than a lap later for the Roman when he lost the front on the apex of a high speed left hander, sending the shocked #3 cartwheeling through the gravel trap and into his first retirement of the year.
Biaggi's demise left the top two now 3secs clear of Bayliss, the Australian now a lonely third, with the frantic battle for fourth between Melandri, Checa, Ukawa and Hayden taking place over 5secs behind him.
Gibernau, riding the screaming 'unsilenced' RCV, continued to reel in Rossi, and after studying the Italian for several laps dived inside the Repsol rider into turn one, on lap 20 – but Rossi appeared to want him to lead...
The #46 then hounded the three-times 2003 race winner, shadowing his every move and making 'dummy' overtaking manoeuvres at almost every turn in an attempt to either unsettle Sete or simply plan his final attack.
The championship top two circulated in nose-to-tail formation right until the penultimate lap when Gibernau attempted to escape, but Rossi responded and the two began the last lap just 0.23secs apart.
Gibernau led most of the lap, but Rossi stuck to his plan and outbraked the Spaniard on the downhill left hander with just a few turns to go. Vale then took a defensive line into the final turn to ensure his victory - but bobbled slightly as he did so.
By contrast, Sete swung through the apex and cut inside the reigning world champion as the pair began a frantic uphill drag race to the flag. With momentum on his side the Spaniard ducked behind his fairing and beat a shell shocked, and fuming, Rossi by just 0.06secs – fantastic.
Gibernau couldn't contain his delight as he crossed the line, while Rossi was left shaking his head – and looking decidedly 'sulky' on the podium, his loss made painfully worse by Gibernau's ecstatic celebrations and more than one 'firm' stare was exchanged between the pair.
Looks like Vale will have plenty to think about in the two-week gap to Brno.