On September 11, 1973, Augusto Pinochet seized power in Chile over Salvadore Allende. Pinochet's reputation, hopefully, precedes him. In the course of seizing power, he immediately went to work "disappearing" or just outright killing his opponents. Many of the opponents were shipped to Estadio Nacional, where they were tortured, raped, beaten, and often killed.
Meanwhile, the 1974 World Cup was looming, and Chile and the Soviet Union were paired against each other in a playoff. Winner goes to the Cup in West Germany.
It was a two-legged tie. The two tied 0-0 in Moscow, and Chile picked Estadio Nacional as the venue for the second leg. The Soviets- even they had standards- were horrified. The national federation appealed to FIFA for a change of venue.
The Soviets learned of the atrocities through a visit from a human-rights organization which, for some reason, Pinochet had allowed to visit. Things were spruced up for the visit, but the human-rights organization didn't buy it for a second.
FIFA organized a fact-finding mission, which given their findings, generated approximately zero actual facts, writing (pdf file, page 13):
In reply to our precise question concerning the stadium, [minister of National Defense Patricio Carvajal Prado] said that in a couple of days the stadium will be at the disposal of the sports organizations as it is expected that the interrogation of the remaining detainees will be terminated (our italics) and most of them will have gone home (p.4).
And in visiting Estadio Nacional:
As mentioned before, the stadium is at present being used as a 'clearing station' and the people in there are not prisoners but merely detainees whose identity has to be established (a large number of foreigners without valid documents)...The stadium is under military guard and entry is only with a special pass. Inside the outer fencing everything seemed to be normal and gardeners are working on the gardens. Inside the stadium itself the seats and pitch were empty and the remaining detainees were in the dressing and other rooms. The grass on the pitch is in perfect condition as were the seating arrangements (p.4).
The match was ordered to go ahead as scheduled, seeing as "life is back to normal". The Soviets fired off a telegram stating that they would not show up, with federation head Granatkin stating that "Soviet sportsmen cannot at present play at stadium stained with blood of Chilean patriots". Similar sentiments poured in from other countries, but FIFA stuck with its line.
The Soviets stayed home. The Chileans showed up.
That was not a highlight. That was the entire match.
FIFA head Sir Stanley Rous would be voted out of office just prior to the World Cup, with this episode part of a larger tendency to be tone-deaf towards world politics, and was replaced by Joao Havelange. Chile would be bounced in the group stage after three boring matches, including two draws, and forward Carlos Caszely would become the first player to receive a red card in a World Cup (they were introduced in 1970, but nobody was sent off then).