Paraguay-based CONMEBOL also hit Boca with a $200,000 fine and ordered the club to play four home games behind closed doors and another four away games without its fans.
Four River Plate players were taken to hospital after they were sprayed with an irritant by fans of their bitter rivals on Thursday, causing their Libertadores Cup derby to be abandoned at halftime.
The River Plate medical team had said the players were suffering inflammation of the cornea and needed days to recover.
The rivalry between the two Buenos Aires sides is one of the most heated in the world. It pits Boca, a traditionally working-class team, against up-town rivals known as the "Millionaires".
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The last 16 second leg tie at Boca's Bombonera stadium was deadlocked at 0-0 when the incident occurred in the tunnel as the players came out for the second half.
Following CONMEBOL's decision, reached at an emergency session, River advanced to the quarter-finals where they will face Brazil's Cruzeiro.
The incident was just the latest in a long line of violent events to blight football in South America.
In 2013, a Bolivian fan was killed by a flare fired by Corinthians fans during a Libertadores match.
In Argentina, an average of five people died each year in fan-related violence between 2000 and 2009, according to reform group Salvemos al Futbol, cited in a recent Insight Crime report.
Most of the deaths are related to fights between the barras bravas, Argentina’s hooligan firms.
(Reporting by Daniela Desantis, writing by Sarah Marsh; Editing by Peter Rutherford)
