Marc McNulty and Kal Naismith were on target as Pompey returned to winning ways at Stevenage.
Gary Roberts teed-up McNulty to open the scoring midway through the first half and send the large travelling support wild with delight.
And Naismith then came off the bench to double their advantage and secure a maximum haul of points at the Lamex Stadium.
Paul Cook made two changes from the side that drew at Exeter earlier in the week.
A fit-again Roberts was thrown straight into the starting line-up following a hamstring injury, while Gareth Evans also returned.
Conor Chaplin and Naismith both dropped to the bench, where they were joined by Michael Smith, who had recovered from a calf problem.
Pompey started the game with plenty of attacking impetus and Evans was inches away from meeting an excellent Ben Davies delivery after just three minutes.
Roberts was then unable to force the ball home after Stevenage stopper Jamie Jones had flapped at another cross from the marauding right-back.
And Roberts had another chance soon after, but his long-range effort was comfortably kept out by Jones.
The Blues were dominating the opening exchanges, but Boro came close to forging ahead on 19 minutes after winning a series of corners.
The last of them fell to Michael Tonge inside the box, with the midfielder hooking the ball over his head, but also over the crossbar.
Pompey were soon back down the other end of the pitch and period of extended pressure ended with Evans having an effort blocked.
But they did break the deadlock on 22 minutes after Roberts did well to steal possession in the middle of the pitch.
He slid a precise pass through to McNULTY, who latched onto the ball and confidently slotted home to take his individual tally into double figures.
The game lost some of its sparkle after that, becoming a scrappy affair that was punctuated by plenty of free-kicks.
Tom Conlon glanced a header narrowly wide for the hosts, while Lee Cox was unable to find the target from the edge of the box.
But the Blues ended the half on a high and Evans sent a low drive rolling inches past the post before Roberts headed wide from an Enda Stevens cross.
Pompey survived a scare early in the second half after Christian Burgess was penalised for a foul on Conlon just outside the box.
The Stevenage midfielder picked himself up to take the free-kick and saw his curling effort tipped over by Fulton.
That aside, however, it had been fairly uneventful since the restart, with little happening to excite a flat crowd.
Roberts brought the game back to life on 58 minutes, however, when he dispossessed Ronnie Henry and surged forward.
But the angles were against the midfielder and his first effort was pushed clear by Jones, while the second flew into the side netting.
Michael Doyle was then left in space 25 yards out and Jones had to push his speculative shot over the bar.
Pompey soon received a bit of good fortune at the other end of the pitch when Byron Harrison inadvertently got in the way of Tom Pett’s goal-bound effort.
Both sides were now looking capable of adding to the scoring and Luke Wilkinson had to hack clear a low Evans shot, with McNulty waiting to pounce at the far post.
Cook made a double switch on 71 minutes as McNulty and Roberts made way for Smith and Naismith.
Stevenage were trying to push men forward in search of an equaliser, but wasted a good opportunity when Harrison and Connor Ogilvie got in each other’s way.
And Pompey made them pay for their profligacy by doubling their advantage on 82 minutes.
Kyle Bennett did well to feed a pass through to NAISMITH, who raced onto it and slammed home to open his account for the club.
There were a few nervous groans from the away end when the fourth official signalled six minutes of stoppage-time.
But – as the heavens opened in Hertfordshire – the Blues comfortably saw out the closing stages to claim all three points.
Stevenage (4-2-3-1): Jones; Henry (c), Wilkinson, Franks, Ogilvie; Cox (Kennedy 60), Conlon; Pett (Parrett 80), Tonge, Hedges (Marriott 72); Harrison
Subs not used: Day, Wells, Johnson, Gorman
Pompey (4-2-3-1): Fulton; Davies, Burgess, Webster, Stevens; Hollands, Doyle (c); Evans, Roberts (Naismith 71), Bennett (Freeman 85); McNulty (Smith 71)
Goals: McNulty 22, Naismith 82
Subs not used: Bass, Clarke, Barton, Chaplin
Referee: Kevin Johnson