Two-time winners Internacional defeated 10-man Tigres 2-1 to win the first leg of their Copa Libertadores semi-final.
Andres D'Alessandro and Valdivia scored in the opening 10 minutes for the Brazilian outfit before Hugo Ayala pulled a goal back in the 23rd minute on Wednesday, reports Xinhua.
But Ayala turned from hero to villain just before the hour when he was sent off following a second yellow card for a bad foul on Nahuel Guzman.
The return match will be played at the Mexican side's Estadio Universitario on the outskirts of Monterrey next Wednesday.
In the other semi-final first leg played on Tuesday, Argentina's River Plate beat Paraguay's Club Guarani 2-0 in Buenos Aires.
