Pompey may well have held a commanding lead before the hosts took the lead, with Dave Kitson guilty of missing some glorious opportunities.
The first of those chances came when he headed Liam Lawrence's perfect cross wide from close range when he really should have scored. David Nugent then raced clear of the Reading defence and forced Alex McCarthy to spill his shot, only for Kitson to have his close range rebound tipped over by the Reading goalkeeper.
The former Royal wasn't the only player guilty of wasting good openings as Jonathan Hogg tamely shot wide from the centre of the box after some good build up play.
Brian McDermott's men had offered little going forward but took the lead after a counter-attack from a Portsmouth corenr.
Jimmy Kebe ran into the Pompey half and passed to Jem Karacan who teed up Shane Long who wasn't closed down quick enough, allowing him to drill the ball past Ashdown who seemed to dive over it.
The main talking point of the game would arrive soon after as Long sprinted through on goal and was chased by Ricardo Rocha. Referee Kevin Friend judged the Portuguese defender to have professionally fouled the Irishman in the box, issuing a straight red card to him much like he did when Pompey played Sunderland last season, which also saw Friend incur the wrath of the Portsmouth fans that night.
The decision sent the Pompey fans into fury as it seemed that Long went down easily after running across Rocha. Also, TV replays have confirmed that the "offence" took place outside of the box and so no penalty should have been awarded.
Long made no mistake in dispatching the fortunate spot kick to make Pompey's task significantly more difficult. David Cotterill was sacrificed as Aaron Mokoena came on to fill the void left by the departing Rocha.
The second half saw Reading sit back and protect what they had but ten man Pompey gave a good account of themselves going forward.
Kitson's bad day got worse as he inadvertently blocked Hayden Mullins' goalbound effort and later on there was a goalmouth scramble that ended with the Reading defence putting the ball out for a corner, only for Friend to award a goal kick instead.
It should be noted that Reading had a goal disallowed for handball, but they were happy to coast the second half as Pompey huffed and puffed in a match they were unlikely to draw, let alone win.
The only real positive to take from the game was the return of Danny Webber after over a year out of the game.
Unfortunately there were a couple of sour incidents in the crowd toward the end of the match with Sulaiman Al-Fahim taking a lot of abuse from the Pompey fans as he exited the ground having sat amongst us during the game.
Then, at the end of the game, some of Pompey's idiot contingent decided to try and jump the segregation so they could get at Reading's idiot contingent who were goading us. Even Steve Cotterill came over to fans and beckoned them down so not to cause trouble and eventually the situation was diffused.
Carl Dickinson also seemed to argue with some fans after the dust had settled. It wasn't what you would call a "good day at the office" that's for sure.
So, at the end of the day, Portsmouth are still six points behind the team in sixth position (Reading, who have a game in hand on us) but a miracle is now required if we're going to extend the season beyond May the 7th.
Pompey Player Ratings
Jamie Ashdown: 5 - Should have saved the first goal.
Ritchie De Laet: 6 - Got forward well.
Ricardo Rocha: 6 - Unlucky to be dismissed.
Greg Halford: 6 - Steady showing.
Hermann Hreidarsson: 6 - Wasn't bested by Reading's wingers.
Hayden Mullins: 7 - Played the anchor role well.
Jonathan Hogg: 5 - Spurned a superb opening.
David Cotterill: 6 - Sacrificed after Rocha's red card.
Liam Lawrence: 7 - Getting back to his best.
David Nugent: 6 - Running caused problems to Reading's defence.
Dave Kitson: 4 - Woeful return to former club.
Substitutes
Darryl Flahavan
Carl Dickinson
Aaron Mokoena (Cotterill 44): 6 - Slotted in fine.
Joel Ward (Hreidarsson 78): N/A - Didn't see much of him.
Nadir Ciftci
Kanu
Danny Webber (Nugent 85): N/A - Good to see him back.