The Seasiders kept up the pressure and Cherries keeper Neil Moss did well to hold on to a Simon Gillett drive and then Moss saved bravely at the feet of Ben Burgess, before scrambling a Shaun Barker header off his goal-line.
Bournemouth finally cracked in the 35th minute. A long and patient build-up by Blackpool saw them string together a dozen passes, before Burgess' final touch set Forbes free and the right winger, who had his best game since joining the Seasiders, made no mistake from 15 yards out.
It took Bournemouth 41 minutes before they finally won a corner but that was cleared with ease by the Blackpool defence in which Ian Evatt was outstanding alongside Latvian Kaspars Gorkss, who was taken off the bench just before the kick-off after Michael Jackson was taken ill during the pre-match warm-up.
Bournemouth rallied a little in the second half but most of their best moves broke down on the edge of the Blackpool box.
In the 50th minute Blackpool consolidated their lead. Again some good build-up work allowed David Fox room down the right and his inch-perfect cross was volleyed home by Burgess at the far post.
In the 60th minute the Cherries finally got a shot on target when Paul Rachubka was forced into a low save by Marc Wilson's free-kick.
James Hayter, who came on as a half-time substitute for Bournemouth, tested Rachubka in the 75th minute with a long distance effort, but Blackpool got their act together and finished in style creating chances and dominating midfield.