Alfie Stanley’s opener at Swindon was not enough for Pompey Academy to halt their recent run of defeats.
The prolific striker (pictured) produced a composed finish to give the young Blues an early lead in the Youth Alliance League.
But Ollie Case and Anthony Lynn both struck to ensure the Robins went in ahead at the break, while a breakaway goal for Harry Parsons wrapped things up in the second half.
Professional development phase coach Liam Daish said: “We started really well on a difficult pitch and got our noses in front through a really good goal from Alfie.
“But we lost possession to concede the equaliser and another individual error was punished to ensure we were behind at half-time.
“Cutting them out is something that we’ve been speaking about for a while now because it’s costing us.
“We went out after the break and dominated on the ball, but Swindon were very disciplined and got bodies behind the ball.
"We’ve probably been victims of our own success in recent weeks because teams are pressing us higher up the pitch and applying a lot of pressure."
“The boys kept trying to do the right thing and worked extremely hard, although we were lacking a bit of creativity in the final third.
“Then we conceded another goal from a Swindon break. That was their tactic and – fair play to them – it worked very well.
“We’ve probably been victims of our own success in recent weeks because teams are pressing us higher up the pitch and applying a lot of pressure.
“We’re looking a little bit vulnerable at the moment, especially in possession in the defensive third, and need to make more right decisions at the right time.
“I certainly don’t think we’ve been playing poorly, although it’s a disappointing run and the lads have been frustrated.
“They’ll work hard to put things right and I’m confident they will come good, but you can’t legislate for some of the goals we’ve been conceding and have to cut those errors out.”
Pompey: Pitman; Kavanagh (c), Robb, Kelly (Bruce 70), Rew; Teggart, Bridgman, Storey, Brook (Bell 61); Stanley, Anderson (Lee 61)