Pompey Academy ended up on the losing side in a seven-goal thriller against Swindon at Furze Lane.
The young Blues made a bright start in their Youth Alliance League opener and Matt Mayes (pictured) converted Dan Smith’s cross to break the deadlock.
And the lead was soon doubled, as Freddie Read’s corner was nodded down by Smith for Matt Casey to tap home.
But Swindon then struck four times in an incredible 20-minute spell at the end of the first half, with Elliot Duggan’s brace and goals from Jordan Edwards and Jacob Barncroft turning the match on its head.
Smith reduced Pompey’s deficit from the penalty spot following the interval after Bradley Lethbridge had been brought down in the box.
But Alan McLoughlin’s Robins managed to hold on for the victory, despite the Blues applying plenty of pressure.
Lead professional development phase coach Mikey Harris said: “We started the game brilliantly and the first 20 minutes were played almost entirely in their half.
“We scored two very good goals – one from a set-piece and the other a great finish from open play by Matt Mayes.
"Swindon got one back and the momentum seemed to shift."
“Then there were numerous chances to extend our lead further, but unfortunately we were not able to take any of them.
“Swindon got one back and the momentum seemed to shift. They scored four before half-time and although we could have done more to stop them, you have to give credit where it’s due – two were fantastic quality.
“We went from 2-0 up and looking comfortable to somehow being 4-2 behind. It was a big lesson for the boys and we spoke at half-time about getting back to what we were doing so well early on.
“They did that and pulled one back. We were then committing men forward and had to deal with some counter-attacks, with Matt Casey making a great clearance from the line.
“We piled on the pressure and if there had been another 10 minutes we might have won the game, but sadly it wasn’t to be.”
Pompey: Collins; Dandy (Johnston 60), Brooks, Casey, Hancott; Chandler (Stanley 83), Smith, Read, Flint (Maloney 60); Lethbridge (Whiting 68), Mayes
Sub not used: Pitman