Phil Smith's verdict: Sunderland's effective gameplan unravels as worrying and hard to fathom trend strikes again
Sunderland have now had a player sent off in just under a quarter of their League One games.
They have had to play well over 200 minutes in those games without an eleventh man.
It is to their immense credit that this was the first time they have ended up on the losing side.
Even against the league leaders, backed by their biggest home crowd in seven years, there was a brief moment where they looked like they might salvage a remarkable result.
A fine move saw the excellent Reece James tee up Max Power. His cross was perfect and Luke O’Nien halved a two-goal deficit.
Just moments later, a Lynden Gooch cross just evaded substitute Alim Ozturk as the outstanding travelling support wondered if something special was on the horizon.
Portsmouth, though, were ruthless.
They were excellent in exploiting the gaps left behind and in truth they could and should have ended the second half with more than three goals in the bag.
Sunderland’s red card habit is hard to fathom.
It is certainly not a reflection of a side that cannot keep its discipline.
There have been two clear reds that Jack Ross never quibbled with, wild kicks from Max Power and Bryan Oviedo against Peterborough.
They were poor lapses from experienced pros but Power’s other two were both contentious in the extreme.
Glenn Loovens’ dismissal at Fratton Park was one that Ross felt was harsh given a change in guidelines.
He felt Loovens had not tried to deliberately bring Oli Hawkins do and so that while it was a clear penalty, he should not have seen red.
He also, like many of the Sunderland players, felt Lee Brown was lucky to avoid the same fate for an incident with George Honeyman in the first half.
What can be said for certain is that it was a lapse from the centre back to allow Oli Hawkins through and it was that lapse which cost the Black Cats the game.
They may only have lost one game in five when reduced to ten, but they have also only won one.
Six points from five is below the rate needed for promotion and it is a key reason why Pompey now have an eight-point advantage in the table.
The biggest frustration for Sunderland was that their application in the first half had been excellent and they had just about shaded the game.
Portsmouth started with expected intensity but they got little joy from the Black Cats.
Luke O’Nien and Reece James were excellent in the wide areas where the hosts have had so much joy this season and Jack Baldwin looked back to his best in the middle.
Slowly Sunderland were able to get a foothold in midfield and create some good openings for Duncan Watmore to get free in the channels.
After a difficult start against the impressive Jack Whatmough and Matt Clarke, Watmore was starting to make things happen and there were clear signs that the gameplan was beginning to produce results for the visitors.
Frustration was beginning to build in the home stands.
Kenny Jackett’s side exploited their opening at the start of the second half superbly.
Their consistency has been impressive this season and they overpowered Sunderland with a confident and clinical streak not seen in any of the teams Ross and his players have faced so far.
Their lead at this stage of the season has been well earned.
Sunderland have bounced back from every setback so far this season and two home games in a matter of days can quickly improve the picture.
It has been a very good first half to the season so far but the red cards have prevented it being a perfect one.
The Black Cats need more luck when it comes to the big decisions, absolutely.
But they will know they can’t afford any more individual lapses, either.