About 100 Chilean fans broke through a wall and crossed the security checkpoint to try to watch their country's World Cup against Spain, which caused the current champion to collapse.
An hour or so before the start of the game, Chilean fans wearing shirts ran to the Maracana stadium and Chile then won 2-0.
The fans, mostly young people, raced past the big FIFA media center underground in Rio to a corridor they thought would lead to the stands.
After entering, they realized that this was not the case and broke a temporary wall.
According to a reporter from The Associated Press at the scene, this caused the metal locker to crash on the ground.
Security guard Diego gonvis said: "I am the only one standing outside.
Suddenly they pushed down the fence and just pushed it away.
"A fan was grabbed by the security guard and dragged away.
Some fled, while others were locked on the floor, while police took them away in droves.
At least one female fan was injured and taken outside in a wheelchair.
The security guards took control of the situation within 15 minutes and the game started on time.
Spain's defeat marked the end of the team's recent dominance in international football.
They have won in the past three major international competitions.
Eduardo Vargas and Charles arangiz of Chile scored a goal.
FIFA and the local organizing committee said in a joint statement: "Before the Spanish match against Chile in Maracana, a group of people without tickets forcibly entered the stadium, breaking the fence and excessive safety.
"They were controlled by security guards and did not sit in their seats.
"The situation was quickly controlled and at least 85 intruders were detained, according to the Rio military police.
"The organizers of the FIFA World Cup condemn these acts of violence and we will communicate more information and measures in due course. "