Argentina 1-2 Cameroon — Italy 1990

Reigning world champions Argentina were stunned 1–0 by Cameroon in Italy 1990's opening match, making it the first time a defending champion lost their opener since 1962. Despite playing with two men sent off, Cameroon capitalized on a François Omam-Biyik header in the 67th minute. This upset outperforms #8 Saudi Arabia vs. Argentina in tournament stage significance, as Cameroon's victory propelled them to the quarterfinals—the first African team ever to reach that round. The 38-year-old Roger Milla, brought out of retirement, scored four goals in the tournament, a remarkable feat considering he was older than the typical World Cup striker.