Save for a quick swap of position on lap twelve, Biaggi continued to keep Haslam at bay, only for the Italian to drop to third with just five laps remaining after an error that allowed both Haslam and Crutchlow through.
Quickly regrouping, Biaggi swiftly dismissed Crutchlow for second before riding up to the back of Haslam and snatching the lead back down the home straight into turn one with less than two laps remaining.
Despite Haslam's best efforts, he couldn't wrestle the position back off Biaggi, leaving the 'Roman Emperor' to celebrate a fine double triumph – the first time Aprilia have won two consecutive races since Troy Corser did so at Valencia in 2001.
Lifting him to second in the overall standings, Biaggi still has a 16 point deficit to make up on the consistent Haslam, whose second place finish keeps the Suzuki man on top by a comfortable margin.
Despite crossing the line just six tenths behind Biaggi, Crutchlow never looked likely to convert his pole position into a race victory, although third position does go a long way to reviving Yamaha's fortunes after a dismal weekend in Australia.
Two more strong results for Checa also keeps him in the hunt overall, the Spaniard even moving ahead of factory Ducati rider Michel Fabrizio after capitalising on a dismal weekend for the Xerox-backed concern.
While his team-mate claimed the spoils up front, Camier courted his own attention with another strong ride to fifth place, ahead of fellow Britons James Toseland, who secured a solid sixth place finish having started a lowly 15th, and Shane Byrne.
Although some way off where he would prefer to be, Noriyuki Haga at least had the mild satisfaction of beating Sylvain Guintoli to eighth after a lengthy battle, the pair having also caught and passed Troy Corser towards the end of the race, the BMW rider fading once again having run inside the top five initially.
Michel Fabrizio completed his wholly unsatisfying weekend in 11th on the second Ducati Xerox, ahead of Ruben Xaus, Tom Sykes, Lorenzo Lanzi and Max Neukirchner.
The World Superbike Championship now moves on to Valencia for the third round of the season in two weeks time.