Rarely threatened defensively - Jamie Butler was forced into one serious save all night, Callum Butcher blocked another goalbound effort - the lads stayed in control in terms of possession and territory and happily stroked the ball around at St Mary's, especially after the home side were reduced to 10 men just after Alex Olsen's winning goal on the hour.
In the end, the Norwegian striker's finish from Danny Rose's defence-splitting pass was enough to book a home tie against Chester City in round four.
"There were reasons why this was going to be a difficult game," reflected Alex at St Mary's. "First of all, there was the mental hurdle of our first game in the competition after what happened to us in the third round last season and then the fact that we'd comprehensively beaten Southampton earlier in the season.
"No matter how much you try and enforce the fact that this is a different game with different circumstances, knowing you won 6-0 might be there at the back of the players' minds, but they coped with everything.
"When Southampton went down to 10 men we showed a level of maturity beyond our years to keep the ball for long passages and not surrender possession.
"We felt their biggest threat would come from a set-piece, so we tried not to give them too many easy opportunities to load our box up.
"I didn't think we were ever under the cosh and we simply kept the ball longer than they did and that stopped any momentum they tried to build. Overall, it was an exceptional performance."
Alex Inglethorpe felt our Under-18s showed a maturity beyond their collective years to overcome a tricky hurdle at Southampton in the third round of the FA Youth Cup on Wednesday night.