Pompey Academy suffered a 3-2 Merit League defeat to Leyton Orient, despite taking the lead in the capital.
Harry Anderson fired them ahead with his 18th goal of the season, only for some poor defending to see the hosts turn the match on its head.
The Londoners netted twice before the break and strengthened their advantage after it, before Harry Jewitt-White (pictured) reduced the Blues’ deficit.
Professional development phase coach Liam Daish said: “It was a difficult day on a bumpy pitch that wasn’t conducive to passing football.
“Harry gave us an early lead, but we conceded a soft equaliser, with nobody taking responsibility for closing the player down.
"It was a difficult day on a bumpy pitch that wasn’t conducive to passing football."
“We then got caught ball-watching from a short corner, while after starting the second half well, there was another situation that we didn’t deal with.
“But we battled away and thanks to honest endeavour and hard work from Dan Gifford to chase down a lost cause, we got one back.
“There were chances to draw level that we couldn’t take and we needed to do more in and out of possession.
“Overall, it was a scrappy game and weren’t good enough defensively in 1v1 situations. That caused us problems.
“But there were good individual performances, with Izzy Kaba in particular playing really well at the back.”
Pompey: Manderson; Dockerill, Cadman (Dawson 80), Kaba, Hughes; Simpson, Jewitt-White; Payce, Gifford, Spurway; Anderson (Greenough 71)