Villa looked to be cruising to victory as goals from Benteke and Gabriel Agbonlahor earned them a 2-0 half-time lead.
But the npower League One side, who had already overcome Stoke in this season’s competition, fought back through two goals from substitute Miles Storey before Benteke had the final say.
SWINDON: Foderingham, Devera, McCormack, Flint, McEveley, Ritchie, Miller, Ferry, Roberts (Louis Thompson 69), Benson (Williams 51), Collins (Storey 75).
ASTON VILLA: Given, Lowton, Herd (Stevens 30), Vlaar, Lichaj, Weimann, Ireland (Bent 83), El Ahmadi, Bannan (Delph 82), Agbonlahor, Benteke. Ref: Stuart Attwell (Warwickshire).