Universidad de Chile sealed a 2-0 win over Nacional to advance to the last 16 of the Copa Sudamericana, although the match was called off before full-time after an official was hit by a missile thrown from the stands.
It was the second such incident in as many days in the competition, with assistant referee Milciades Saldivar targeted by an object thrown from the stands.
That prompted referee Antonio Arias to call off the match, with Universidad awarded a 2-0 victory - 3-0 on aggregate - having led by that scoreline on the night following goals from Eduardo Vargas and Matias Rodriguez.
Tuesday's match between Olimpia and Emelec was also halted eight minutes from time after missiles were thrown at visiting goalkeeper Martin Silva. Olimpia progressed with a 2-1 away win over the Ecuadorian club.
Libertad have joined them in the last 16 courtesy of a 1-0 win over La Equidad. Ignacio Canuto scored the only goal after 18 minutes to wrap up a 2-0 aggregate victory and secure a meeting with Sao Paulo in the next round.
Universidad will take on Flamengo.