Referee Andres Cunha had to be protected by riot police after a late penalty kick saw River Plate reach the Copa Libertadores final at the expense of Gremio.
Cunha, in consultation with VAR, awarded a penalty against Gremio's Bressan for handball after 86 minutes. Bressan was given his marching orders for a second yellow card but refused to go quietly. The penalty was eventually taken in the fifth of 14 minutes of added time, and was converted by Gonzalo Martinez to send River through to the final.
Having lost the first leg of the semi-final 1-0 on home soil, River knew they had to win to keep alive their hopes of the Copa Libertadores title. And, despite dominating proceedings, they fell a goal down after 35 minutes as Leonardo struck for Brazilian side Gremio. But River kept pushing forward and got a deserved equaliser after 81 minutes as Rafael Borre struck to level matters.
River Plate won the second leg 2-1 and went through on the away goals rule. The Argentine side, beaten 1-0 at home in the first leg, went further behind when Leo Gomes scored for the Brazilian holders after 35 minutes in Porto Alegre. River Plate were still two goals behind on aggregate with nine minutes of normal time left, but then Rafael Borre scored.
Uruguayan Cunha then sparked the penalty drama in the 86th minute and was surrounded by Gremio players, with riot police entering the field to protect him during the nine-minute delay that followed before the kick was taken. After the long wait, Martinez buried from 12 yards to send River through on away goals.
In incredible scenes, riot police were forced to protect Cunha from furious Gremio players as River celebrated reaching the final.
It sets up a potential blockbuster game against Argentine rivals Boca Juniors, who have a two-goal lead going to Sao Paulo for the second leg of their semi-final against Palmeiras. River are bidding for a fourth Copa Libertadores title having previously won the competition in 1986, 1996 and 2015. Should Boca progress from their semi-final, they will be looking for a seventh crown having tasted glory in 1977, 1978, 2000, 2001, 2003 and 2007.