Posh came from behind to win 7-1 at Roade thanks to goals from Hannah Hipwell (2), Jess Driscoll, Niamh Conner, Keir Perkins, Beatriz Borque and Ellen Marson.
Yasmin Green struck twice as Netherton won 3-0 at Moulton. Ellie Hannan also scored.
Posh are back in National Midlands League action on Sunday (January 23) at second placed Long Eaton. Cambs Division One leaders Netherton have a city derby game at Cardea.
Posh Foundation made it 10 wins in 10 games in Cambs Division Three with a 16-0 win over Cambourne. Keira Swanson (4), Callie Tancred (4), Andreia Oliveira (4), Kacey Sharman (3) and Jess Broadway scored.
Tia Smith cracked a double hat-trick for Stanground as they beat Saffron Walden 7-1 in the Under 12 Division. Kate Conkey also scored. Stanground started the season under the Peterborough Northern Star banner. Northern Star’s Under 18 team beat St Ives 4-0 in a League Cup tie.
Kiera Swanson scored twice as Glinton & Northborough Under 16s beat Rushden & Diamonds 5-1 in a Northants Cup quarter-final tie.