Gaston Fernandez gave the Argentines the lead in the first minute but Libertad took control and were threatening an equaliser when Brazilian referee Carlos Simon awarded the hosts a penalty in the 62nd minute.
Miguel Samudio was judged to have fouled Marcos Angeleri as he cleared the ball. Samudio, who protested vehemently, was sent off and Mauro Boselli converted.
Boselli added a third for the three-times champions when he headed in Juan Sebastian Veron's cross in the 70th minute of Thursday night's game in La Plata.
Teixeira converted a penalty in the 57th minute to wipe out Gabriel Cichero's third-minute strike for the visitors, who had Rafael Castellin sent off after only 20 minutes for elbowing.
Ismael Villalba scored Cuenca's winner on a rain-soaked pitch in the 69th minute.
