A lone Rever goal in the 48th minute of the match was enough for Atletico to see off visitors Coritiba at Estadio Raimundo Sampaio.
Coritiba finished the match with 10 men after Rafinha received a second yellow card with two minutes of the match remaining.
They lead by one point from Vasco da Gama and are three points ahead of Fluminense, who defeated Sao Paulo 2-1 at home.
Leandro Euzebio gave hosts Flu the lead after 36 minutes at Estadio Sao Januario, with Cicero levelling for Sao Paulo a minute before the break.
Fred restored the home side's advantage six minutes into the second half, and they went on to record all three points in Rio de Janeiro.
Also on Thursday, fourth-placed Gremio were held to a 0-0 draw in their match away to Ponte Preta.