Southport have now lost their last six games and have only scored once in that time. Their woes were compounded after 37 minutes when Chris Brass - who is on loan from York City - was given his marching orders in the first half for deliberate hand-ball as Brian Tinnion's shot was about to cross the line.
The Shots took the lead after 27 minutes through a Matt Somner pile-driver, and doubled their advantage 11 minutes later through Darren Barnard's penalty awarded for Brass's goal-line offence.
For all their efforts, Southport were poor all afternoon and Shots keeper Nikki Bull could have been concerned at the possibility of getting frost bite, such was the level of his inactivity!
Aldershot showed their intention from as early as the second minute and were unfortunate not to take an early lead. Tinnion's free-kick from outside the area found Somner, whose header hit the post and bounced back to the safety of Port keeper Steve Dickinson's arms.
Somner, however, was not to be denied as Aldershot struck when Southport lost concentration. Somner gathered the ball 25 yards out, the Port defence were nowhere, and when he let loose a right-foot thunderboltDickinson was rooted to the spot, the ball nestling in his net.
The Shots had further opportunities through Nick Crittenden, and John Turner and Ashley Vincent who both combined well, but Dickinson caught Vincent's scooped effort.
As Aldershot went for Southport's jugular, Brass dived low down to stop Tinnion's strike crossing the line and was shown a straight red card. Barnard stepped up and converted the penalty to make it a long miserable journey back to Merseyside for the visitors.