Daisy McLachlan and Eilidh Currie were on target as Pompey Ladies beat Cardiff to stretch their winning run to four games.
They were first to go close following a slow start in south Wales, with McLachlan seeing her shot saved by Estelle Randall after cutting inside from the left.
Amelia Southgate then made a terrific last-ditch tackle at the other end, with the referee ignoring desperate penalty appeals from the hosts.
It was end-to-end stuff, with a long-range effort from McLachlan narrowly clearing the crossbar, while Corey Williams had a pop for Cardiff.
But the Blues broke the deadlock early in the second half when McLachlan arrived at the far post to convert Ellie Kirby’s delivery.
Robyn Levett then ensured they maintained the lead, continuing her fine form by tipping Zoe Atkins’ header over.
And Pompey managed to extend their advantage late on, with Rachel Panting cutting the ball back for Currie to slot home.
"We were professional, resolute and efficient – I’m very proud of everyone involved."
Sammy Quayle soon had the ball in the back of the net again, although this time celebrations were cut short by an offside flag.
Cardiff then hit the post following a late rally, but the visitors had done enough to secure all three points.
Blues boss Jay Sadler said: “We were professional, resolute and efficient – I’m very proud of everyone involved.
“Cardiff is not an easy place to come to and leave victorious, so it’s another positive step in the right direction.”
Pompey: Levett; Kirby, Southgate, Currie, Geer (Peck 90+4); Simmons; Panting, Albuery, Sievwright (Perkins 90+7), McLachlan (Boswell 62); Quayle
Sub not used: James