Pompey were undone by a dreadful defensive display in the opening 20 minutes as they slumped to a 3-2 defeat against Colchester.
The visitors took the lead after just 98 seconds through Gavin Massey, although Jed Wallace levelled three minutes later.
However, a Freddie Sears penalty and a second for Massey gave the U’s a 3-1 lead after only 20 minutes.
Massey came close to a hat-trick and Jabo Ibehre could have also netted during a poor first period from Guy Whittingham’s men.
Liam Walker came on at the break and a spirited second-half display saw the hosts pull a goal back in the 73rd minute with a superbly-worked goal from James Keene.
Yet they couldn’t grab an equaliser, despite six minutes of time added on, and it ended up a seventh successive defeat and now 17 matches without a win in all competitions.
Whittingham made just the one change, with Sodje coming in for his debut in place of Gabor Gyepes.
That meant the former Notts County defender partnering Ricardo Rocha in the centre of the Blues’ defence.
Gyepes was instead among six players on the bench, although it wasn’t long before he was thrown into the action.
When the match got under way, Pompey suffered a nightmare start as Colchester took the lead after just 98 seconds.
Sears delivered a superb ball from the right and there was Massey in the middle of the six-yard box to steer a shot home.
It was a lead which would last until the fifth minute, with Dan Butler’s right-wing corner carving out the equaliser.
The left-back’s delivery was sent to the far post where Wallace was on hand with a deft flick to send the ball into the far top corner of the net.
The action continued with Colchester winning a penalty in the 15th minute after Sodje’s obvious trip on Sears.
The former West Ham man stepped up to take the spot-kick and calmly sent Simon Eastwood the wrong way.
Pompey were shaky at the back and Ibehre’s cross from the right was then narrowly glanced past the far post by Massey’s backheel.
Yet in the 20th minute the hosts did fall behind 3-1 with that man Massey the goalscorer.
The ball was cleared only so far as the midfielder, who was lurking outside the box, and his shot took a wicked deflection off Rocha and looped over the helpless Eastwood.
Rocha came off in the 27th minute with what appeared to be a pull, Gyepes coming on to replace him in the centre of defence.
Massey could have completed his hat-trick after just 29 minutes when George Porter crossed from the right and the two-goal scorer slid the ball wide at the far post.
Walker came on for David Connolly at the break, yet it was a mistake from Josh Thompson in the 48th minute which almost gave the hosts a lifeline.
A pass down the middle was headed past his own keeper by the Colchester skipper, but he just got back to hack the ball off the line with Keene chasing.
It was bright stuff from Pompey after the interval and Shaun Cooper crashed the shot over the bar following a fine move.
In the 67th minute, Keene won a free-kick after a Thompson challenge and Butler’s delivery was headed just past the post by Sodje, but Sam Walker had it covered.
Pompey did reduce the deficit, though, in the 73rd minute with a goal of stunning quality.
Ertl started it off with a backheel and the slick move saw Walker flick the ball over Thompson for Keene to fire in a magnificent half-volley from an acute angle.
A total of six minutes were added on at the end but there was no successful comeback as Pompey lost again.
POMPEY 2 (Wallace 5, Keene 73)
COLCHESTER 3 (Massey 2, 20, Sears 16 - pen)
Att: 11, 132
Pompey: Eastwood, Butler, Rocha, Sodje, Moutaouakil, Wallace, Ertl, Cooper, Harris, Connolly, Keene. Subs: Smith, Walker, Reed, Sutherland, Gyepes, Webster.
Colchester: Walker, White, Thompson, Okuonghae, Clifford, Wright, Sears, Ibehre, Porter, Massey, Wilson. Subs: Drey Wright, Cousins, Bean, Morrison, Bond, Compton, Eastman.