Ronaldo ends Corinthians goal drought
The former FIFA World Player of the Year scored his 11th goal of the season eight minutes into the second half when he took a long pass from Elias, dribbled past Indio and shot low into the bottom corner of goalkeeper Lauro's net.
Jorge Henrique opened the scoring for Corinthians midway through the first half, finishing off a fine move on the wing by Marcelo Oliveira.
The winners qualify for next year's South American Libertadores Cup, taking one of five Brazilian berths in the competition.
The visitors had forward Leandro sent off in the 79th minute, 22 minutes after coming on as a substutite, after being booked for two nasty fouls.
Inter, who host the return leg in Porto Alegre on July 1, were without three leading players -- Argentine playmaker Andres D'Alessandro is injured while striker Nilmar and fullback Kleber are with Brazil at the Confederations Cup in South Africa.