The left-back drilled a 30-yard drive into the top right corner in the third minute of stoppage time to hand the Rio outfit their first win of the campaign on Saturday, reports Xinhua news agency.
Brenner had given the hosts the lead just after the half hour mark when his low shot rebounded in off the near post.
Gremio equalised two minutes later courtesy of an own goal from Igor Rabello.
The result at the Nilton Santos stadium lifted Botafogo to second in the 20-team standings with five points from their opening three matches. Reigning Copa Libertadores champions Gremio were eighth, a point further back.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
