The hosts got off to the perfect start when they caught the away side napping within the first minute as Jeff Hughes played in namesake Lee Hughes, who slid the ball under Cherries keeper Darryl Flahavan.
County continued to dictate play but were left to rue not making the most of their dominance when, after 70 minutes and against the run of play, Bournemouth equalised.
A perfectly judged run by Cherries midfielder Marc Pugh saw him coolly chest down Harry Arter’s ball and finish in style.
They were not level for long, though, as seven minutes later, Krystian Pearce towered over the Cherries defence to meet an inch-perfect Alan Judge corner with a thumping header.
And four minutes from time substitute Montano turned superbly and fired into the top corner past a helpless Flahavan.