Pompey Academy wasted a host of chances as they crashed to a 3-1 defeat at Swindon in Merit League One.
Elliott Duggan and Ollie Rejek both found the target late in the first half to give the hosts a commanding advantage at the interval.
Josh Flint (pictured) converted a cross from Leon Maloney to reduce the deficit, only for Rejek to wrap things up for the Robins on the break.
Academy manager Mark Kelly said: “It was an attractive, flee-flowing contest during the early exchanges and we created some decent openings, while they kept the ball well.
“Leon had an opportunity when he was sent one-on-one, while Bradley Lethbridge, Dan Smith and Oscar Johnston also might have done better.
“Instead we fell behind from a long ball over the top that should have been dealt with. Our keeper came out too late and their lad nipped between him and Matt Casey to score.
"There’s a pattern emerging – you can’t have that many opportunities and not take them."
“Our heads perhaps dropped a little bit after that and we were caught not marking properly on the edge of the box, as Swindon bundled their way through to get another.
“We made changes at the break. Jordan Brooks and Matt Mayes came straight back after finishing their loan spells, so we moved to three up top.
“Going back over the game, we worked out that we had 26 chances in the second half and Josh took one of them, but there should have been more goals.
“It was all us from that point and we pushed forward, but our concentration levels dropped a bit and they were able to kill the game off.
“There’s a pattern emerging – you can’t have that many opportunities and not take them. We’re also conceding too many goals without making the opposition work for them.
“It’s costing us games and the boys have to learn from that, as you need to find some consistency if you want a career in this sport.”
Pompey: Tombs (Pitman 68); Dandy, Casey, Hancott, Flint; Maloney, Read, Whiting (Brooks 46), Johnston (Mayes 46); Lethbridge, Smith