Matthew Sorinola's first-half strike was enough to see MK Dons Under-23s pick up all three points in their latest Central Development League outing.
A number of first-team players were fielded for the clash with Southend, with deadline day addition Andrew Fisher starting for the first time in a Dons shirt. His defence consisted of Charlie Pattison, Regan Poole, Baily Cargill and Matthew Sorinola.
David Kausmu, Hiram Boateng and John Freeman made up the midfield with Jordan Bowery, Kieran Agard and Dylan Asonganyi making up the front three.
Both sides took their time to find their feet in the clash with both MK Dons and Southend having efforts end wide of the goal within the opening 10-minutes.
The best chance of the opening stages fell the way of Richard Taylor who forced Fisher into a save at his near post.
Meanwhile, the Dons best chance came via good work from Hiram Boateng. After beating two men to work his way into the box, Boateng’s cross was punched away from Jordan Bowery by the Southend keeper.
Kasumu then denied Rush with a last-ditch tackle on the edge of the box just as the Southend striker looked to shoot.
In a half of few chances, it was Matthew Sorinola who gave the Dons the breakthrough just four minutes before the half-time whistle. Having kept the ball for a sustained period of time Boateng played in Sorinola, the Southend defence stood still and awaited the offside flag, however it never came. With Agard available for the tap-in, Sorinola opted to go himself and converted into the back of the net. 1-0.
As the half-time whistle was about to blow, Fisher denied Rush as he was in on goal.
And just seconds into the second half, Fisher once again prevented Rush, this time turning behind his side-footed strike. From the following corner, Southend thought they were level, only for Rush to be flagged offside following the flick on.
Southend were then reduced to 10-men as Richard Taylor was shown a second yellow for his foul on Kasumu.
The Dons next chance came via a counter-attack down the right, Poole drove the Dons forward down the right before finding the run of Pattison. His cross was cleared over the bar by the recovering Southend defender, the following corner was headed over by Poole.
Sorinola then went in search of his second goal of the afternoon, his chipped effort was turned behind for a corner.
With 70-minutes on the clock, the Dons were denied their second after a superb Callum Taylor save. The move started after Pattison won possession just inside the Southend half before he carried the ball to the edge of the box. He then played in Agard out wide who delivered into Asonganyi, his effort was turned behind by Taylor.
With 15-minutes left to play Kinali had the chance to draw Southend level, he found some space on the right side of the box, but was unable to test Fisher.
Boateng then had his effort go wide of the goal after some good work to create space for the shot from the midfielder.
Jordan Bowery was then denied a solo-goal as Southend defender handballed his effort on the line The referee, however, ignored the claims awarding a corner instead. Boateng had his header saved.
MK Dons XI: Fisher, Pattison, Sorinola, Kasumu (Harley 61), Poole, Cargill, Freeman, Boateng, Bowery, Agard, Asonganyi.
Goals: Sorinola (41).