Jacques Maghoma scored the only goal of the game against the long-time leaders of Group A of the FA Premier Academy League.
What impressed coach Pat most was keeping a clean sheet.
He said: We spoke a lot in the week about the soft goals we'd been giving away and we worked a lot on defending set-pieces.
There were a lot of corner against us against Southampton and I was really pleased with the defence in keeping a clean sheet.
I couldn't pick any individual out - as a team I would have to say well done' because it was our best result of the year.
Pat Holland revealed that hard work on the training ground paid off as our Under-18s produced their best result of the season against Southampton.