With Biaggi, who himself had taken several laps to dispose of his team-mate for fifth, beginning to loom just behind, Haslam finally got the break he needed as he capitalised on an error by Toseland that put him wide at Westland on lap twelve.
Haslam may have found a way through but Toseland had no opportunity to relax and he was immediately pounced upon by Biaggi, who took just four more laps to get past following an identical error at the same bend.
In that time, Toseland had been caught by Camier, Crutchlow and also Jonathan Rea, who was rocketing back into contention having spent much of the race lingering towards the bottom of the top ten.
Indeed, Rea was the man on the charge as he quickly passed Crutchlow before pulling off an outstanding move on both Camier and Toseland to rise into fifth position. Camier himself had just found his way past Toseland with an impressive move on the entry to the Mineshaft, only for Rea to get them both on the outside of the following bend.
At the head of the field though, Fabrizio was cruising to the fourth World Superbike win of his career, a triumph that brings a dismal run of recent form to a close and sees him back on the podium for the first time since the Phillip Island season opener.
Checa kept up the pressure in second but would finish just over a second adrift. Nonetheless, the Spaniard has now pulled clear in the battle for third overall, while he is now comfortably the highest-placed Ducati rider in the overall standings.
Haslam used the four laps it took for Biaggi to get past Toseland to good effect as he held on for his eighth podium finish in eleven races, in turn eking out his advantage in the overall standings to five points.
Rea was a strong fifth from 12th position on the grid as he and Camier pulled away from Toseland at the finish, although the former champion did have the satisfaction of keeping Yamaha team-mate Crutchlow at bay for seventh and eighth respectively.
Like Rea, Jakub Smrz put on a late charge but could do nothing more than ninth position, while Sylvain Guintoli and Luca Scassa filled positions ten and eleven after passing a fading Troy Corser
late in the race.
Wild-card Sheridan Morais made solid progress to work his way up to 13th on the EmTek Aprilia, ahead of Ruben Xaus
and Shane Byrne, who completed the points' paying positions.