An energetic start by the Hammers saw Robbie Keane giving them a 2nd minute lead before England striker Darren Bent equalised for Villa before half-time.
West Ham, without talisman Scott Parker following an achilles tendonitis problem, had chances to win the game in the second-half before Agbonlahor stole the points for the Midlands side in the last minute of play.
To compound the Hammers’ problems Manuel Da Costa and Gary O’Neil both suffered injuries which may keep them out for some of the remaining games of the season.