While River Plate versus Boca Juniors was marred by an apparent tear gas attack, Racing Club and Emelec both reached the last-eight.
Racing Club and Emelec both advanced to the Copa Libertadores quarterfinals Thursday, while the Superclasico between Boca Juniors and River Plate was suspended.
As River's players made their way onto the pitch after halftime at La Bombonera, around six seemed affected by some form of irritant - potentially pepper spray or tear gas.
Leading 1-0 on aggregate following its win at home last week, River's players and staff were understandably unwilling to proceed following the apparent attack from the fans of their archrival.