Pompey slipped to their first defeat in six league games as Filipe Morais inspired a Stevenage victory at the Lamex Stadium last night.
But the diminutive Portuguese forward had some wretched defending from the Blues to thank following his two goals in the 2-1 home win.
Firstly, he was left criminally unmarked and in acres of space at the far post to head home unopposed in the 14th minute.
Later, his 61st-minute right-wing cross was allowed to creep through a crowded penalty area and in at the far post with no touch applied.
Both were appalling defensive lapses from a Pompey side who appeared to have discovered new-found steel in recent weeks.
Sandwiched in between was Jon Harley netting three years to the day since he last scored a goal – on this occasion firing home from 30-yards.
There were also plenty of bright moves from Michael Appleton’s men, particularly during the second half, when Brian Howard bossed the midfield.
Certainly no shame in their performance against a high-flying Boro side who have maintained a push towards the top of League One this season.
Reflecting that was the noisy away following who provided a string of Appleton songs, topped off by the occasional expletive aimed in Burnley’s direction.
However, ultimately, those two crucial defensive lapses which gifted Morais his brace proved so decisive.
With some inevitability, the occasion also saw Carl Dickinson booked on his Pompey return, although the loanee from Watford put in a steady display.
Nevertheless, Appleton will be left to reflect on two awful mistakes at the back which meant his side returned home without at least a point his team rightfully deserved.
Before the match, Dickinson was granted his second Pompey debut – coming in for Mustapha Dumbuya at left-back.
The Sierra Leone international was moved to the bench, with Lee Williamson given the nod to continue at right-back.
That was the only change to the team who impressively defeated Shrewsbury 3-1 at Fratton Park on Saturday.
Meanwhile, talented youngster Adam Webster was missing through England under-18 duty.
Noel Blake’s side take on Italy tonight at Mansfield, with the young defender pushing to feature following his maiden call-up.
The only other absentee from Appleton’s squad was Darel Russell, who remains out with the hamstring injury he picked up last month.
When the match got under way, it was Howard who would be the first to test the Stevenage keeper.
On nine minutes he picked himself up, having been fouled, and struck a 30-yard free-kick which was straight into the chest of Steve Arnold.
Minutes later, Howard’s right-wing corner was cleared as far as Williamson, who fired in a sweetly-struck volley from outside the box which was again comfortably dealt with by Arnold.
Yet it was the hosts who took the lead in the 14th minute.
Lucas Akins fired in a cross from the right and Morais was there unmarked and in acres of space to steer a diving header past Mikkel Andersen.
On 23 minutes, another Howard free-kick from long range saw Arnold fail to hold, but striker Izale McLeod slipped on the turf as he attempted to pounce on a rebound and the opportunity went.
Boro, however, were undoubtedly an attacking threat with their clever passing and slick play and goalscorer Morais fired one just over the bar from 30 yards out.
Then a wonderful cross from the overlapping David Gray down the right saw Lubomir Michalik manage to snake out a foot and prod away for a corner.
On the half-hour mark, a Pompey counter saw McLeod fizz in a shot-cum-cross from the right which was somehow missed by the desperate dive of Wes Thomas at the far post.
Thomas then saw his shot inside the penalty area deflected for a corner following great play by Dickinson and Harley in the build-up.
It was better stuff from the visitors and on 40 minutes a desperate melee inside the box saw Williamson, Thomas and Buzsaky all fire in attempts, before the latter then volleyed over.
On the stroke of half-time Morais went agonisingly close to doubling his side’s lead with a 35-yard first-time lob which only narrowly cleared Andersen’s bar.
The Blues came close to equalising two minutes into the second half when Thomas intercepted Bondz N’Gala’s backpass.
The striker rounded the keeper and shot towards an empty net, only for Mark Roberts to appear from nowhere and brilliantly lift the ball off the line for a corner.
But on 51 minutes the visitors did equalise, through Harley’s first goal for the club.
Howard cut across field and fed the ball into the feet of the former Chelsea man who cleverly spun round and drilled the ball into the bottom corner of the Stevenage net.
The two teams were on level terms for just 10 minutes, though, as that man Morais ensured the home side regained their lead.
The forward fired in a cross from the left which somehow eluded everyone inside the box and crept in at Pompey’s far post.
The visitors piled forward in search of an equaliser but the Boro backline stood firm with some gutsy defending in dangerous situations.
Even with five minutes of time added on, the leveller would not arrive and Pompey suffered their first league defeat since September 22 at Notts County.