Pompey scored two early goals to beat Coventry 2-1 and secure their first away league win since October.
They broke the deadlock after just 10 minutes when Jade Widdowson picked out Nadine Bazan down the left and the skipper crossed for Samantha Quayle to powerfully head home.
And the lead was almost immediately doubled, as Natasha Stephens latched onto Molly Clark’s pass over the top.
Her effort was parried clear by Susan Woods, but Rachel Panting was first to the loose ball and coolly slotted into the net.
Pompey kept pushing forward and had strong appeals for a penalty turned down before Widdowson’s header was cleared from the line.
But Coventry reduced the deficit before half-time, with Stephanie Smith smashing a shot past Emily Paines.
It was the visitors who looked the more threatening side after the interval and Bazan, Stephens, Quayle and Shannon Albuery all went close.
"We’ve got a fantastic group of players and the mentality has been brilliant."
And Paines made sure those missed opportunities did not prove costly, with key saves to deny Helen Dermody and Jade Brook.
Blues boss Jay Sadler told the club’s official YouTube channel: “I’m really pleased with the performance – not many teams will come here and get anything against Coventry.
“Our preparations were spot on. We stayed up the night before, had a team meal, did our analysis and the girls were fantastic.
“We’ve got a fantastic group of players and the mentality has been brilliant. It’s a privilege for me to work with them.
“We got our early goals and although it got a bit nervy in the second half, our pressing and positioning were superb.
“The subs who came on made a big impact and I felt that overall we were worthy winners. There wouldn’t have been any justice if we’d conceded at the end.
“My message to the team is that we’ve won two sprints, but this is a marathon. We’ll enjoy the win, but now we prepare for the next one.”
Pompey: Paines; Peck, Southgate, Widdowson, Bazan (c) (Kirby 77); Quayle, Simmons (Barron 66), Clark, Stephens; Panting (Currie 89), Albuery
Subs not used: Perkins, James