In Wellington, former Lower Hutt player Emiliano Tade led Central's charge to the final with a hat-trick that included two penalties.
His seventh minute spot kick was all that separated the teams at halftime but Patrick Fleming's 52nd minute dismissal for a second yellow card earned from a clash with Central keeper left Miramar with a mountain to climb.
Paul Urlovic made it 2-0 in the 57th minute and Adam Dickinson extended the lead further in the 82nd minute to kickstart a final flourish from the five-time Chatham Cup winners.
Seven minutes from fulltime Miramar goalkeeper Sacha Nathu brought down Tade to earn an early shower and the Argentinean striker slotted the resulting penalty, before completing his hat-trick with Central's fifth goal in the first minute of injury time.
A forgettable day for Miramar was compounded in the fourth minute of additional time with another red card, this time to Tom Doyle, with Daniel Koprivcic converting the resulting penalty to wrap up the 6-0 win.
The venue for the final will be confirmed during the week, with North Harbour Stadium - the host of 11 of the last 14 finals - due to host provincial rugby on the weekend of August 25-26.
Results from Sunday's semifinals in the Chatham Cup football competition:
At Caledonian, Dunedin
Caversham 0 Lower Hutt City 4 (Hamish Watson 38, Pomare Te Anau 63, Taban Mokaii 67, Andrew Coad 84). HT: 0-1.
At David Farrington Park, Wellington
Miramar Rangers 0 Central United 6 (Emiliano Tade pen 7, pen 83, 90+1, Paul Urlovic 57', Adam Dickinson 82, Daniel Koprivcic pen 90+4). HT: 0-1.