However, the Italian was on a charge and was up to fifth behind Haga on lap five, just as he was attempting to find a way past Spies. When his first attempt was rebuffed, Fabrizio took advantage and moved past his team-mate.
Fabrizio would go on to relieve Spies of third by lap six, just as Haga himself was being overtaken by a recovering Biaggi for fifth. Biaggi's push would take him past Spies just a lap later, the Roman this time making the pass stick.
Leaving Haga and Spies to dispute fifth position now, the Japanese rider made his move at turn three on lap eight by dipping beneath his rival and forcing him to sit up. Luckily for Spies, the seven-strong field had already been reduced to six following Haslam's second retirement of the day, his departure leaving a sizeable gap to Leon Camier in seventh.
Back at the front, Byrne was continuing to hold steady in the lead, the Briton showing some fighting spirit to keep Rea behind after the Northern Irishman nosed ahead briefly on lap five.
However, after ten laps out front, Byrne was overtaken by Rea into turn one after giving up a slipstream to his rival, the Sterilgarda man being demoted to third a lap later when he was passed by a flying Fabrizio.
His relentless rise up the order continued on lap 14 when he slipped past Rea into the lead, before proceeding to slow the pace down in order to allow Haga to make up some ground on the front runners.
The strategy was certainly helping Haga as he took fourth from Biaggi, who made a mistake on lap 15, before getting the better of Byrne for third with just four laps of the race remaining. At the same time, though, Rea had fought his way back into the lead after slipstreaming Fabrizio down the home straight and out-braking him into turn one.
There was a further change of position just behind when another error by Biaggi on the ailing Aprilia allowed Spies up to fifth position. Biaggi would go on to try and get past Spies on repeated occasions, only to run off the circuit as he struggled to get his RSV-4 slowed down in time.
As the field headed into the final lap, Rea led Fabrizio over the finish line, but an error out of the final turn had allowed the Ducati onto the back of the Honda, Fabrizio's tow proving enough to get him past as they dived down the hill for the final time.
Rea fought back at turn five, but would simply out-brake himself into the bend, forcing him to run off the circuit, allowing both Fabrizio and the close following Haga through into first and second.