Curtis Bateson came close for North Ferriby early on, hitting wide when the ball broke to him in the area.
Danny Emerton also had a shot cleared off the line, but Braintree had half-chances of their own in a tight first half.
Steve Housham's visitors carved out further opportunities after the break, and Sam Topliss struck the crossbar with a fierce effort.
Braintree boss Hakan Hayrettin then made an inspirational substitution, bringing on Reece Hall-Johnson on the hour and 18 minutes later, the midfielder netted the winner for the hosts.
Report supplied by the Press Association.
Match ends, Braintree Town 1, North Ferriby United 0.
Second Half ends, Braintree Town 1, North Ferriby United 0.
Goal!  Braintree Town 1, North Ferriby United 0. Reece Hall-Johnson (Braintree Town).
Substitution, North Ferriby United. Ryan Kendall replaces Curtis Bateson.
Substitution, Braintree Town. Sam Corne replaces Kyron Farrell.
Substitution, Braintree Town. Reece Hall-Johnson replaces Kristopher Twardek.
Substitution, North Ferriby United. Matt Dixon replaces Ross Armstrong.
Second Half begins Braintree Town 0, North Ferriby United 0.
First Half ends, Braintree Town 0, North Ferriby United 0.
Mark Gray (North Ferriby United) is shown the yellow card.
First Half begins.
Lineups are announced and players are warming up.
Braintree bolstered their survival prospects at the expense of North Ferriby, whose defeat at Cressing Road saw them sink to the bottom of the table.