Flamengo started the better side with more intensity and urgency. All of that paid off soon enough as they got the opening goal just after six minutes of the game. Everton Ribeiro created found good space for himself and broke the deadlock early on.
Fla continued pushing for another goal but a lapse in defence cost them minutes later. Their lead didn"t last long as they conceded a penalty in the 14th minute. Osvaldo was brought down by Isla in the box and Juninho made no mistake from the spot to grab the equalizer for his side.
Flamengo continued to dominate but failed to restore their lead despite seeing about 60% of possession.
Fortaleza goalkeeper Felipe Alves was busy in the first half and had to make four key saves to keep his side level in the game.
The second half started with Gabigol coming on in the 46th minute. Flamengo even saw more of the ball and continued to push for a winner.
Their persistence would pay on late in the game. Two minutes from time, substitute Gabigol found himself through on goal and gave Fla a crucial goal that sealed the winner.
The result means Flamengo have now secured their third successive victory in the Brazilian Championship. With 14 points, Fla moved up to second place with only two less than Inter. However, they can still be overtaken by São Paulo, Atlético-MG, Vasco and Fluminense during the round. Fortaleza remain in 10th place on the standings with eight points.
For their next outing, Fortaleza take on Sport Recife on Wednesday while Flamengo travel to face Fluminense for the ninth round of the Brasileirão.