The players are working really hard on the training groundMartyn Olorenshaw
Despite having 64% possession and boasting real periods of control on the South Coast, a young Blues side, that were without four second-year scholars called up to the Under-23s, came unstuck against a ruthless Southampton outfit.
Brandon Khela and Jobe Bellingham did score in the second-half for the visitors, but their efforts only served to half a deficit that totalled four at the break.
This included a hat-trick in the opening 45 for Kamari Doyle, who ended the game with five counters.
Fedel Ross-Lang and Dominic Ballard were also on the scoresheet for the saints in a nine-goal encounter.
Speaking after the loss, Lead Under-18s Coach, Martyn Olorenshaw, was able to pick out the positives as Blues' youngsters continue their transition into the Category 1 Academy games programme.
He told BCFC.com: "There was a good response at half-time and for about 25-30 minutes we were much better; in control and could have made it 4-3. But near the end, they have just punished us again.
"We have got to learn quickly from it. The errors are easily avoidable with better decision making. The response at half-time was really good, I can't fault the players. We got ourselves back in the game and we could have made it really interesting. We have just got to put together a much longer and sustained performance.
"It will take some time to adapt, the game is quicker at this level. The players are working really hard on the training ground to do that, I can't fault that. It is just a step up."
Blues are back in league action on Saturday at Wast Hills Training Ground, with Tottenham Hotspur making the trip to the West Midlands.
Blues: Brooks, Nguepissi, Carsley (Khela 46), Ogor, Oni, Williams (Dance 46), Home, Hall, Patterson, Wakefield, Bellingham.
Goalscorers: Khela 51, Bellingham 59.
Booking: Ogor 30 and second yellow 86.