rearguard

noun

1. (attributive, often)The rearmost part of a force, especially a detachment of troops that protect the rear of a retreating force.
2. (attributive, often)The defence, collectively the defenders.

   “Mancini's side only showed enough ambition when it was too late and by then battle lines were drawn as James Collins and former City captain Richard Dunne fought a magnificent rearguard action at the heart of Villa's defence.”