Jesus Datolo scored in the 89th minute to give Atletico a 1-0 victory and lift them to within 11 points of Corinthians, who can secure the title by winning any of their final four matches as they top the standings with 76 points.
Atletico fans began their traditional chants of "I Believe!" - made famous when they beat the odds to lift the Libertadores Cup in 2013 - when Datolo's last-gasp goal went in.
Despite Sunday's success, it would take a turn-about of unprecedented proportions for the Belo Horizonte to overcome the league leaders. Corinthians require just two points from their final 12 to lift the trophy.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"The title hasn't been won but it's on the way," Corinthians coach Tite said after his side beat Coritiba on Saturday in front of a record home crowd of 43,688.
Young striker Lucca came off the bench to score a crucial goal for the second time in a week and his strike, added to Jadson's earlier penalty, gave Corinthians three points.
Their next game is at second-from-bottom Vasco da Gama on Nov. 19.
At the other end of the table, Vasco moved off the bottom for the first time in months with a brilliant 2-0 win at Palmeiras.
They were the only one of the bottom six clubs to win, although Joinville, who fell into last place, can leapfrog them if they beat Santos in Sunday night's match.
Just six points separate the bottom six clubs, with four going down at the end of the season.
(Editing by Pritha Sarkar)
