The timely strike kept Jay Sadler’s team firmly involved in an exciting FA Women’s National League Southern Premier title race.
Pompey sat second after Sunday’s victory, though they are now down to third after Oxford United leapt above both them and Ipswich by beating MK Dons 4-1 in midweek.
Pompey are two points adrift of Oxford, having played a game more, but Oxford still have to visit Westleigh Park on April 16.
The Blues are a point behind second-placed Ipswich, with both teams having just five games left. Completing a four-horse title race, Watford are a further two points behind Pompey, with a game in hand.
Even if Pompey end up winning the league, that does not mean they will automatically be promoted into the second tier of women’s football.
Instead, the Southern Premier champions will face the Northern Premier champions in a one-game play-off to decide which of the two teams wins promotion.
Nottingham Forest, who trounced Pompey 5-0 in the semi-final of the National League Cup earlier this month, currently top the Northern Premier.