Leyton Orient lost for the third time at home this season as Bristol Rovers collected three badly needed points.
Craig Disley opened the scoring for Rovers with a header before Agogo scored a penalty in the second half after he was fouled by John Mackie.
Gary Alexander pulled one back after good work from Justin Miller before Agogo made it 3-1 after 82 minutes with a strike from 18 yards.
Daryl McMahon then reduced the deficit further with a right-foot volley.
Leyton Orient: Garner, Barnard (Tudor 45), Dolan, Miller, Mackie, Keith, Simpson (Carlisle 59), Easton, McMahon, Alexander, Steele (Echanomi 66).
Subs Not Used: Morris, Zakuani.
Booked: Easton, McMahon, Mackie.
Goals: Alexander 75, McMahon 89.
Bristol Rovers: Shearer, Hinton, Ryan, Elliott, Hunt, Disley (Campbell 78), Leary, Anderson, Gibb, Agogo (Louis 90), Walker (Bass 84).
Subs Not Used: Carruthers, Forrester.
Goals: Disley 15, Agogo 54 pen, 82.
Ref: M Russell (Hertfordshire).