Southern League title-chasers Southampton WFC play two divisions below their FAWPL opponents but it was they who scored first and despite then having their lead quickly overturned, they twice equalised before Pompey took command with three goals late on to secure a ninth successive Hampshire Cup.
At a foggy Havant & Waterlooville FC, Southampton began well and took a 15th-minute lead when Jane Yeates buried a diving header from Meg Vella's cross,
Eight minutes later and the favourites had not only levelled but gone in front. Quayle raced through to beat the keeper for the first and Gemma Hillier then struck home from 25 yards.
Just before the break, Southampton were gifted an own-goal as Pompey keeper Courtney Trodd missed Eilidh Currie's back pass.
Portsmouth pressure paid off on 68 minutes as they gained the advantage again, with Quayle's effort in the box taking a wicked deflection.
But moments later Vella beat the on-rushing Trodd to make it 3-3.
On 77 minutes Nadine Bazan whipped in a ball that went in possibly with the assistance of Quayle, who then made sure of a hat-trick by losing her marker and rounding the keeper.
It was 6-3 in added time as Player of the Match Quayle found space to again attack the Southampton goal.
Photos - @pompeyfcladies