As it gears up to open the World Cup against Croatia in Sao Paulo, Brazil could do worse than look back in the history books to avoid any complacency. Over the years, the World Cup has seen its fair share of shock results in the opener, which until 2006 usually involved the defending champion, not the host as is now the norm. The most famous surprises occurred in Italy in 1990 and in South Korea in 2002. In the former, a downward header from Francois Omam-Biyik was enough for Cameroon to defeat defending champion Argentina 1-0 in Milan in a game that was also notable for the sending off of two Cameroonians. Twelve years later, France, many people's favorite to retain the title, lost by the same scoreline to Senegal in Seoul after a goal by Papa Bouba Diop. Defeat in the opening game doesn't necessarily mean all hope is lost. Though France was eliminated in the group stage in 2002 without scoring a goal, Argentina somehow managed to scrape through to the final in 1990.