From Japan's softball team winning over the undefeated USA to Steven Bradbury clinching Australia's first gold medal.
Let's have a look at the topmost upsetting moments at Olympics.
2002 Salt Lake City, Winter Olympics
Australia's Steven Bradbury was at the last during the last lap. However, his luck helped him as all the other contenders slipped. And, Steven won Australia's first Gold medal.
2008 Beijing Summer Olympics
The USA women's softball team was defeated for the first time by the Japanese team.
2000 Sydney Summer Olympics
Russian legend Alexander Karelin, undefeated for 13years was defeated by Rulon Gardner.
Lake Placid 1980 Winter Olympics
The amateur USA ice hockey team defeated the reigning champions USSR .
2004 Athens Summer Olympics
The mighty Puerto Rico's basketball team defeated the USA's dream team.