Pompey endured a miserable trip to the capital as they were beaten 3-0 in a televised clash with Charlton.
They fell behind to Ryan Inniss’ header after an encouraging opening and Corey Blackett-Taylor ensured the hosts were comfortable at the break.
The Blues made a positive response early in the second half, only for Marlon Pack to be sent off and Eoghan O’Connell to score from the resulting free-kick.
Danny Cowley stuck with the same side – and bench – that drew with Fleetwood on home soil in their last outing.
Tom Lowery and Joe Rafferty had both returned to training following a spells on the sidelines, but were not yet considered ready for selection.
Former Fratton loanee Jayden Stockley was selected up front for the home side, with Craig MacGillivray named among the substitutes.
It was Pompey who made the brighter start and some nice passing play led to their first chance of the game.
A teasing Clark Robertson cross had to be headed out for a throw and when the ball was worked across to Josh Koroma, he fired narrowly wide from the edge of the box.
The visitors then almost took the lead on nine minutes, as Joe Morrell found Colby Bishop and his header was tipped over by Joe Wollacott.
But instead they fell behind, with a corner played to Scott Fraser and his cross nodded home by Inniss at the back post.
Pompey tried to fight back and O’Connell made a key block when Dane Scarlett tried to slide the ball across for Bishop.
Scarlett then thought he had been fouled when trying to meet a teasing Robertson delivery, but referee John Busby disagreed.
The Blues were being undone by some sloppy play, though, and when Michael Morrison lost possession, Blackett-Taylor broke quickly and scuffed a shot narrowly wide.
Fraser then stole the ball from Koroma and Charlie Kirk played an incisive pass through for Blackett-Taylor to calmly slot home.
Pack came close to reducing the deficit late in the first half, but his 25-yard free-kick rippled the side netting after Owen Dale had been upended.
Charlton finished on top, however, and Pack eventually hacked clear after a corner led to a spot of pinball in the area.
Jes Rak-Sakyi then bulldozed his way forward and hit a fierce shot that Josh Griffiths did brilliantly to beat away.
Half Time: Charlton 2 Pompey 0
Cowley made a double switch at the break, with Morrison and Koroma replaced by Zak Swanson and Michael Jacobs.
The latter immediately looked lively and fired one shot wide before sending in a corner that somehow evaded everyone on its way out of play.
But it took another superb stop from Griffiths to stop the visitors falling further behind, with the keeper getting his fingertips to a curling effort from Blackett-Taylor.
A foul on Morrell gave Jacobs a chance with a 25-yard free-kick and although it was on target, Wollacott was not overly troubled.
The Blues were dealt a blow just past the hour mark, however, when the midfielder went down injured and had to be replaced by Ronan Curtis.
And there was more bad news to come moments later after the already booked Pack was penalised for a foul on Fraser.
It initially looked as though Busby would take no further action, but Stockley was quickly in his face and the official decided that the midfielder should be dismissed.
Charlton immediately made the most of their numerical advantage, as the free-kick from Fraser was headed in by O’Connell.
Cowley responded with another double switch, bringing on Reeco Hackett and Jay Mingi for Scarlett and Dale.
And Pompey kept battling away in the closing stages to ensure the Addicks were unable to add a gloss to the scoreline, with Griffiths getting down low to deal with a late Albie Morgan strike.
Charlton (4-4-2): Wollcaott; Egbo, Inniss, O’Connell, Sessegnon (Clare 77); Rak-Sakyi (Payne 71), Dobson, Fraser (McGrandles 79), Blackett-Taylor (Morgan 71); Stockley (c) (Aneke 77), Kirk
Goals: Inniss 17, Blackett-Taylor 31, O’Connell 67
Booked: Sessegnon, Dobson, Morgan
Subs not used: MacGillivray, Campbell
Pompey (4-4-2): Griffiths; Ogilvie, Morrison (Swanson 46), Raggett, Robertson (c); Dale (Mingi 68), Morrell, Pack, Koroma (Jacobs 46 (Curtis 62)); Scarlett (Hackett 68), Bishop
Sent off: Pack (two yellow cards)
Booked: Morrell
Subs not used: Oluwayemi, Pigott
Referee: John Busby
Attendance: 13,456 (2,374 Pompey fans)