Leeta Rutherford was on target as Pompey won on the road at Ipswich for the second weekend in succession.
Following their extra-time triumph in the League Cup quarter-finals last Sunday, this latest victory secured three precious points in the battle for promotion to the Championship.
Jay Sadler made a trio of changes from the side that progressed to the last four, as Georgie Freeland, Dani Lane and Emily Pitman came in for Ella Wild, Annie Rolf and Ava Rowbotham.
The visitors got off to the perfect start at the AGL Arena by taking the lead in the very first minute of the contest.
A cross from Pitman was cleared only as far as RUTHERFORD, who fired the ball home on the half-volley from the edge of the box.
The Tractor Girls tried to hit back, although a delivery into the box by Sophie Peskett was confidently claimed by Hannah Haughton.
There was then concern for Pompey when Jazz Younger went down and required treatment, eventually being helped off and replaced by Ali Hall.
It was, unsurprisingly, proving to be another close encounter between the two title hopefuls, with clear-cut opportunities at a premium.
Ipswich did go close to a leveller when Maria Boswell’s free-kick was met by Lenna Gunning-Williams, whose shot clipped the crossbar.
And there was a chance for the Blues to double their lead just before the break, with Poppy Soper getting down well to deny Pitman.
Half Time: Ipswich 0 Pompey 1
The visitors also started the second period quickly, although a sliding Daisy McLachlan could not quite make a connection with Sophie Quirk’s low delivery.
Ruby Doe then met a Leah Mitchell cross at the other end of the pitch, but could only nod the ball straight into the arms of Haughton.
The skipper was called into more demanding action just past the hour mark, rushing off her line to deny Peskett.
Pompey were looking fairly comfortable, however, and Soper managed to prevent Nicole Barrett from getting a shot away.
The defender’s corner then caused chaos in the Ipswich box and a close-range Pitman effort was deflected behind.
Sadler turned to his bench to freshen things up as the seconds started to wind down and it was the visitors still looking more likely to add to the scoring.
Soper again came to the rescue to save a shot from Ella Humphrey, who had been teed-up by fellow substitute Rolf.
But that early goal ultimately proved enough to send the Blues three points clear at the top of the table.
Pompey: Haughton (c); Barrett, Younger (Hall 25), Casley, Collins; Freeland (Rowbotham 86), Rutherford, Lane; McLachlan (Humphrey 59), Pitman (Rolf 78), Quirk
Sub not used: Wild