Beattie opened the scoring in the 58th minute from the penalty spot after Darren Purse had handled Wayne Bridge’s cross before making the game safe eight minutes from time with his 11th goal in eight games.

Birmingham made further changes in the 81st minute, bringing on Govan Karovski and Craig Fagan for ineffective duo Damien Johnson and Aliou Cisse.

Southampton made one change of their own, withdrawing striker Brett Ormerod and replacing him with Jo Tessem, and it was their change that proved more effective as he helped the home side cruise to victory moments later.

The Norwegian crossed from the right for Anders Svensson to flick the ball into Beattie’s path for the striker to gleefully finish at the far post.