Pompey suffered their fourth straight defeat, going down 4-1 at Watford.
They did take an early lead courtesy of Carl Walshe’s (pictured) smart finish but the hosts fought back and were 2-1 in front at the interval.
The Blues tried to find a way back into the game but Watford struck twice in the second half to take the points.
Director of Youth Operations Paul Smalley said: “We lost two of our older players to injuries within the opening 20 minutes and that disrupted our rhythm but we managed to keep competing and played some neat football.
“While this is our fourth successive loss of the season, the first-year scholars are getting adjusted to the rigours of competitive under-18s football and the second-years are consistently producing the performances we expect.
“The result was disappointing but we dealt quite well with an aggressive, competitive and very direct Watford side.
“What is pleasing is that the players are striving to meet both their individual and team performance challenges.
“All the players are receptive, attentive and hard working. The games are an excellent additional learning opportunity which assists them in their progress as young footballers.
“I am sure that in the near future the results will start to change and actually reflect the overall performances.”
Pompey: Gledhill, Tallack, Magri, Ryan, Martin (Harris), Bennett (Colson), Stockford, Tsovolos, Goddard, Seeley (Jennings), Walshe
Sub not used: Fitzharris
Pompey's under-16 side were beaten 3-1 by the same opposition.