A Copa Sudamericana match in Bolivia had to be abandoned midway through the second half after a player was assaulted by a supporter.
Uruguay's River Plate were leading 1-0 away to Bolivian side Blooming in the preliminary stage of the competition when a Blooming fan pulled River forward Henry Gimenez to the ground.
The result is set to stand, with Federico Puppo's 62nd-minute goal making the difference for River. He profited from a mistake by Blooming goalkeeper Andres Jemio after a Jorge Rodriguez corner.
It could be a crucial away goal, with the second leg to come in Uruguay on August 27.
However, Peruvian referee Victor Carrillo decided to abandon the game after the attack on Gimenez. Blooming fans began to throw projectiles onto the field.
The South American Football Confederation (CONMEBOL) are expected to confirm soon whether they award River Plate the victory or resume the game. Blooming's future in the continental championship is in danger.
CONMEBOL inspector Fernando Barriocanal told FOX Sports: "Obviously, there was a security failure. The fan not only entered the field but also hit a player, so the situation is even more serious. The security staff was focused on the game and not on providing security."
Donato Rivas, chief of the River Plate delegation in Bolivia, added: "A disaster could have happened. It went out of police control. The player is shocked but fine and our physiotherapist was also hit by a stone.
"The Blooming president (Carlos Bendeck) offered apologies and we accepted them because he is a gentleman. However, we'll pursue this with CONMEBOL. We'll wait for the referee's report and try to see which decision CONMEBOL will make."
In Quito, Ecuadorian giants LDU claimed a 1-0 home win over Libertad of Paraguay.
Neicer Reasco netted the winner seconds before half-time, getting a rebound after Libertad goalkeeper Bernardo Medina saved a Christian Lara shot.
The second leg of this tie will be played on 25 August.