Scunthorpe 5 Pompey 1
Pompey were dragged back into the relegation dog-fight following a five-goal humbling at Scunthorpe.
A David Syers hat-trick helped the high-flying hosts increase their chances of League Two promotion.
There was a touch of fortune about the first, which took a huge deflection, but the Blues could have no complaints about his other two either side of the interval.
Sam Winnall and Paddy Madden were also on target to complete a miserable trip north for Pompey.
Debutant Michael Drennan came off the bench to reduce the deficit near the end, but it was scant consolation.
Richie Barker made three changes from the side that beat AFC Wimbledon the previous week.
Toumani Diagouraga was handed his debut in the centre of midfield and there were also starts for Wes Fogden and former Scunthorpe winger Andy Barcham.
Ryan Taylor missed out with a groin injury, while Ricky Holmes and Nicky Shorey dropped to the bench, where they were joined by recent arrival Drennan.
The hosts – unbeaten in 15 matches and sitting second in the table – came flying out of the traps and Sonny Bradley was forced to clear Gary McSheffrey’s dangerous low cross over the bar in the opening seconds.
But Scunthorpe kept applying pressure and broke the deadlock with just five minutes on the clock.
It was cruel on the Blues, however, with Syers’ strike taking a wicked deflection off Ben Chorley to leave Trevor Carson flat-footed.
And the Iron almost doubled their advantage in similar fashion moments later, with another Syers effort hitting Chorley and flying inches past the post.
Pompey were not offering much at the other end, although Sam Slocombe had to claim Jed Wallace’s cross before Barcham curled tamely wide.
The game settled down as the first half progressed, although the visitors did create an opening on 26 minutes.
Diagouraga and Fogden combined well on the edge of the box, but the ball was blocked before the latter could find Barcham.
They might have fallen further behind on 34 minutes, however, as Winnall met Eddie Nolan’s cross from deep and glanced a header inches past the post.
But the striker did double Scunthorpe’s advantage soon after, stroking the ball past Carson after swapping passes with McSheffrey.
And it got even worse for the Blues just before the break when Syers drove a shot through a crowded area and into the net.
Nothing seemed to be going Pompey’s way and they were twice denied a goal of their own in stoppage-time, as efforts from both Barcham and Jake Jervis were blocked in the box.
Half Time: Scunthorpe 3 Pompey 0
Barker made a double switch at the interval, with Drennan and Holmes replacing Barcham and Thery Racon.
But that failed to change the tone of the match, as Scunthorpe bagged their fourth of the afternoon three minutes after the restart.
Carson managed to push away David Mirfin’s bullet header, but Madden was first on the scene to poke home the loose ball.
And a punishing afternoon got even worse for the Blues on 55 minutes when Syers converted Hakeeb Adelakun’s low cross to complete his hat-trick.
Worryingly, the hosts still possessed plenty of attacking intent and Madden went close with a ferocious drive that flew narrowly wide.
The 497 travelling Blues fans decided to create their own entertainment, with chants of ‘let’s pretend we scored a goal’ followed by wild celebrations in the AMS Stand.
There was little else for them to cheer, though, with Slocombe enjoying a comfortable afternoon between the sticks for Scunthorpe.
Hat-trick hero Syers made way for Paul Hayes on 71 minutes and he should have added a sixth, only to blaze wide with just Carson to beat.
DRENNAN showed him how it should be done late on, stooping to head home Daniel Alfei’s cross and give the Blues supporters something to cheer.
But the damage had already been done and Pompey made the long trip home knowing that Tuesday’s Fratton test against Accrington had grown in importance.
Scunthorpe (4-4-2): Slocombe (c); Nolan, Mirfin, Canavan, Williams; Adelakun (Hawkridge 79), McAllister, Syers (Sparrow 71), McSheffrey; Madden, Winnall (Hayes 71)
Goals: Syers 5, 43, 55, Winnall 36, Madden 48
Subs not used: Severn, Ribeiro, Dawson, Waterfall
Pompey (4-4-1-1): Carson; Alfei, Chorley (c), Bradley, Painter; Fogden, Racon (Holmes 46), Diagouraga, Barcham (Drennan 46); Wallace; Jervis (Agyemang 82)
Goals: Drennan 85
Subs not used: Smith, N’Gala, Shorey, Padovani
Referee: Lee Collins
Attendance: 4,165 (497 Pompey fans)