Goals from Ben Wright and Andrew Yiadom earned Braintree their first away win of the season at Forest Green.
The Iron went ahead when Jai Reason played in Wright from the left and he drilled a low shot past Matthew Bulman.
Substitute Yiadom sealed the victory in injury time when he expertly lobbed Bulman from the edge of the area.
The best chance for Rovers, who won 6-1 at Alfreton on Saturday, fell to Reece Styche but his powerful effort was well saved by Iron's Nathan McDonald.
Forest Green: Bulman, Hodgkiss, Turley (Imudia 46), Graham, Stokes, Rowe (Matthews 70), Allen (Turk 46), Forbes, Klukowski, Griffin, Styche. Subs Not Used: Bittner, McDonald.
Braintree Town: McDonald, Peters, Paine, Bailey-Dennis, Thomas, Reason, Symons, Davis, James-Lewis (Yiadom 68), Marks, Wright (Chilaka 73). Subs Not Used: Ashlee Jones, Quinton, O'Connor.
Goals: Wright 35, Yiadom 90.
Ref: Tim Robinson (West Sussex).