Pompey recovered from falling behind to secure a thumping League One victory over Cambridge at Fratton Park.
They had failed to make the most of their possession in the opening stages and fell behind to Joe Ironside’s finish.
But Colby Bishop poached a leveller just before the break and it was pretty much one-way traffic in the second half.
Ronan Curtis and substitute Michael Jacobs took advantage of some questionable goalkeeping to give the hosts a commanding lead.
And Connor Ogilvie wrapped up a superb victory that ensured the Blues claimed their first home win of the season.
Danny Cowley made three changes from the side that won on the road at Cheltenham at the weekend.
Tom Lowery made his first start in the centre of midfield, while there were also places for Owen Dale and Curtis on the wings.
It meant that Louis Thompson, Reeco Hackett and Michael Jacobs all had to be content with a place among the substitutes.
Former Pompey defender Brandon Haunstrup started for the visitors, while his fellow academy graduate Adam May was on their bench.
It was a muggy evening on the south coast and tempers were raised early on following a late Liam O’Neil challenge on Lowery.
The home bench were angry that the punishment was limited to a yellow card, leading to some words from referee Chris Pollard on the touchline.
Pompey were dominating possession, although struggling to make any inroads once they entered the final third.
A shot from Curtis was scuffed wide, but Dimitar Mitov’s main problems came from a couple of dodgy back-passes from his own team-mates.
Josh Griffiths had to be alert at the other end, using his legs to deny Shilow Tracey following some sloppy play at the back.
But the visitors did break the deadlock on the half-hour mark, just moments after Griffiths had done well to deny Ironside.
The resulting corner was sent towards the near post by O’Neil and Ironside arrived to neatly convert it.
Pompey initially struggled to respond to that setback and the play was growing increasingly scrappy as the interval approached.
They started to pick things up, though, and Mitov was finally called into action to deny the in-form Bishop in stoppage-time.
But the danger was not over for United and when Dale swung in a cross from the left, Sean Raggett unselfishly played the ball across for BISHOP to tap home.
Half Time: Pompey 1 Cambridge 1
The second half got off to a fast start and Raggett saw a header blocked after meeting Dale’s cross from the right.
Dale then sent a shot narrowly over, while Griffiths had to dive at the feet of Tracey when the action quickly switched to the other end.
But it was the Blues who broke the deadlock on the hour mark after Dale had won a foul wide on the right.
Mitov was unable to keep hold of the delivery from Lowery and CURTIS took advantage to force the ball over the line.
A double switch soon followed, with Lowery and Dane Scarlett getting a warm reception as they made way for Thompson and Jacobs.
And it was JACOBS who increased the lead on 70 minutes, slotting home after a low Curtis delivery from the right was laid into his path by Bishop.
That was Bishop’s last contribution, as he and Dale soon made way for Joe Pigott and Reeco Hackett, receiving rapturous applause as they exited the arena.
Pompey were not done yet, though, and it was Hackett who assisted their next goal, whipping in a cross that OGILVIE got to first to fire home.
It might have got even better, but an audacious attempt from inside his own half by the excellent Marlon Pack did not quite have enough dip.
The midfielder then received a standing ovation as he was replaced by Jay Mingi at the death, with the job well and truly complete for the hosts.
Pompey (4-4-2): Griffiths; Rafferty, Morrison, Raggett (c), Ogilvie; Dale (Hackett 72), Lowery (Thompson 63), Pack (Mingi 90), Curtis; Scarlett (Jacobs 63), Bishop (Pigott 72)
Goals: Bishop 45+2, Curtis 60, Jacobs 70, Ogilvie 77
Subs not used: Oluwayemi, Swanson
Cambridge (4-2-3-1): Mitov; Okedina, Jones, Taylor (c), Haunstrup (Dunk 67); Digby, O’Neil (May 67); Smith, Knibbs (Brophy 67), Tracey (Janneh 76); Ironside (Lankester 81)
Goals: Ironside 30
Booked: O’Neil, Jones, Okedina
Subs not used: Mannion, Rossi
Referee: Chris Pollard
Attendance: 17,702 (460 away fans)