But by the halfway mark it was Barbera who had stolen the initiative, leading the fierce battle for second between Pedrosa and Nieto – the top three now enjoying a one second lead over de Angelis - with world champion Vincent now in the thick of the action in sixth.
Meanwhile, Perugini's race - and perhaps championship - hopes came to a sudden end soon after when, having run wide one lap earlier, he tangled with Dovizioso and hit the dirt – sending the Italian into retirement.
Back up front there was now a battle between three Spaniards, Barbera letting Pedrosa and team-mate Nieto (respectively) back ahead of him as he planned his attack, while de Angelis was fast closing in as he also smelt a chance of his first GP victory.
With three laps to go, the Globet Aprilia rider had despatched Pedrosa - now informed of Perugini's DNF via his pit board and so eager to avoid any fairing bashing in the closing stages - and going all out to upset the Aspar Aprilia one-two up front.
But Barbera and Nieto were involved in their own battle, and certainly weren't giving any extra room to each other simply because they are in the same team. After swapping positions several times it was Nieto, yet to win a GP, who led Barbera (one GP win to his credit) across the line to start the penultimate lap.
Barbera, beginning to feel the pressure from de Angelis, re-passed his team-mate to lead onto the last lap – while Nieto almost ran off track as he tried to slipstream ahead into turn one. Barbera held firm on that occasion, but was passed soon after by Nieto's better momentum, before a firm move saw Hector back in front.
With half a lap to go the team-mates were still bar-to-bar, but Barbera led out of the final turn and must have seen his second GP victory flash in front of him... before he saw Nieto's #22 machine appear under his right elbow as he slipstreamed past to win by just 0.2secs at the flag!
Being the son of a motorcycling legend isn't an easy task, and as he crossed the finish line for the 75th time in his GP career Nieto absolutely exploded in celebration - as only Spaniards (and a certain V. Rossi) can do. Pablo eventually cruised back to parc ferme to be greeted by his father and Aspar team, having practically thanked each of the track side fans personally on his slow down lap.
His victory also made it an incredible 18 125cc races without a back-yo-back winner.
De Angelis was ultimately unable to match the Aspar boys up front, but took yet another podium after holding off the points riding Pedrosa, while Vincent can be proud of his fighting fifth on his Aprilia return.
Full results to follow...
3. de Angelis