In fact, Haslam's demotion would kick-start a remarkable drop for both himself and BMW team-mate Melandri, the pair seeing their lap times increase to drop behind Biaggi, Checa and Sykes in just four laps.
Worse would follow for Melandri, however, when contact with Badovini on lap 19 would see him slip outside the top ten, before pulling into the pit lane when he dropped out of the points' paying positions.
Back at the front, Rea's lead was also under threat, the Ulsterman's advantage having been quickly pegged back by a determined Giugliano, who in turn had Biaggi and Checa for close company in third and fourth positions.
Giugliano eventually made his move for the lead on lap 17, with Rea proceeding to be sat up by following Biaggi and passed by Checa shortly afterwards, pushing him back to fourth.
With Rea's pace dropping off markedly, the battle for victory was reduced to Giugliano, Biaggi and Checa, with the younger of the trio doing a sterling job at keeping both his countryman and his team-mate at bay with some feisty riding.
However, though he was able to maintain the lead for four laps, Biaggi eventually struck with three laps remaining into turn one, with Checa immediately pouncing on his team-mate to go with his rival in second place.
Setting up an exciting last gasp fight for the win, the stark contrast in set-ups would see Checa close up under braking, but the superior straight-line speed of the Aprilia would ultimately give Biaggi the respite needed to complete a very popular victory on home soil.
His first win since the Phillip Island season opener, Biaggi's success has done him the service of increasing his lead in the overall standings to 30 points, while Checa still has much to be pleased with following the qualifying error that left him on the fourth row.
Notching up his second podium of the season, Giugliano crossed the line in third position after a mature performance from the Superbike rookie.
With Rea fading badly, Sykes regained fourth in the closing stages to soften the blow to his title dreams, the Kawasaki rider now at least back up to second place in the standings.