The crucial moment came with five laps to go when Gibernau pulled a one-second lead - his biggest advantage over Biaggi since the Roman had moved into second - and Sete's plan to break the former multiple 250cc world champion before the last laps worked perfectly as he firstly held that gap, while Biaggi attacked, then increased it..
Sete thus began the last lap with a two-second lead, enough to prevent a lunge from Biaggi and careful passing of further lapped riders, now inside the top ten, ensured Max was never in a position to deny Gibernau an emotional home victory.
The Telefonica rider, who'd been playing down his chances all weekend, was as animated as ever when he finally crossed the line to celebrate with the 100,000 plus Jerez crowd.
Biaggi wasn't too disappointed either, and the near 50-second margin between himself and Barros proved that once again he'd raised his game... but once again another rider had raised there's just a tiny bit more.
Nevertheless, both Gibernau and Biaggi are now ahead of Rossi in the title chase, with Sete a point ahead of Max, and Valentino a further two points back.
Indeed, The Doctor could have been further behind had he not managed to hold off a charging Nicky Hayden, the American making an impressive comeback after being bumped down the order early on to close to within a few tenths of Rossi by the flag – how Repsol Honda would have loved it if he'd beaten him...
Behind Hayden, Checa recovered from his mid race fade to finish sixth, ahead of Colin Edwards, while Kenny Roberts picked up his first points of the year with eighth for Suzuki.
Nakano also had a strong end to the race for Kawasaki's first top ten of the year, while Michel Fabrizio gave WCM a dream day by taking tenth, despite his earlier fall.
Abe, Capirossi, Hofmann, Aoki and Hopkins completed both the point's finishers and total finishers after eight riders failed to reach the flag.
Of those, Neil Hodgson was arguably the most unlucky, the reigning World Superbike champion having ridden faultlessly in only his second MotoGP start to rise as high as seventh on lap 17 when he passed Checa... only for his d'Antin Ducati to break down for the second race in succession shortly after.
Race results – Spanish Grand Prix: