Adriano, who signed in March but had only made four appearances due to injury and fitness problems, scored with a characteristic left-footed shot into the top of the net to seal the home win in the 89th minute at the Pacaembu in Sao Paulo.
Corinthians were a goal down to relegation threatened Atletico only 10 minutes earlier and in danger of relinquishing their lead in the standings to Vasco da Gama, who beat bottom team Avai 2-0 in Rio de Janeiro on Saturday.
However, former Portugal striker Liedson headed the equaliser from right-back Alessandro's cross after the visitors from Belo Horizonte had taken the lead 11 minutes into the second half with a header from central defender Leonardo Silva.
Former Inter Milan and Flamengo striker Adriano, who came on in the 68th minute, had done little of note until he received the ball in the box from Emerson and blasted a shot into the roof of the net.
"This goal is very important for me. After more than a year without scoring, to be able to hit such a goal is hard to explain," said Adriano, who by taking off his shirt to celebrate not only earned a yellow card but also showed he was overweight.
"I still have a lot to do but [coach] Tite put his confidence in me and I managed to score at the end," Adriano, top scorer in the championship when he helped Flamengo win the title in 2009, told reporters.
Third-placed Fluminense, who have won 12 of their last 17 matches, kept their title defence alive with a 4-0 rout of fifth-placed Figueirense to remain five points behind Corinthians and three adrift of Vasco.
Their captain Fred hit a hat-trick to take his tally to seven goals in five days after scoring four in Wednesday's 5-4 win over Gremio.
Internacional climbed into the top four, which are qualifying berths for next year's South American Copa Libertadores club championship, with a 2-1 away win over Botafogo, who dropped to eighth after their sixth defeat in seven matches.
America Mineiro's three-match winning-streak, which included victories over Corinthians and Fluminense, in their fight to avoid relegation came to an end with Saturday's 3-1 defeat at Sao Paulo.
