Tawharu picked up a first half hattrick to lead Forrest Hill Milford to a 4-0 lead.
They added a fifth through Jasmine Waldren before Northland pegged one back through Colleen Winstanley with just a few minutes left on the clock.
Northland now head south to take on Claudelands Rovers.
The men's side continued to show why they belong in the Lotto NRFL Division Two as they comfortably accounted for Onehunga Mangere.
Northland started strongly, getting out to an early lead thanks to the boot of Jordan Rudman.
Rudman followed his 12th minute strike with another in the 30th to double Northland's lead.
A Onehunga Mangere error gifted an own goal before Steve Schimmel added a fourth inside the first half.
Onehunga Mangere grabbed a goal of their own before halftime through Stanley Onacha to make it 4-1.
Northland picked up where they left off in the first half with two early goals to Mark Ruddell put the match beyond any doubt.
Northland FC were finding the back of the net with such regularity they even scored in their own net, bringing the score back to 6-2.
Ruddell completed his hattrick with a couple of minutes left on the clock to give them the 7-2 victory.