The Dutch women's water polo team defeated the heavily-favored USA team 9-8, with a goal in the last minute breaking the 8-8 tie. Since the USA was ranked #1 and was the defending world champion, and the Dutch ranked only #9, this was a huge upset.
Stories like this are what make the Olympics so great. You just never know what's going to happen. As Yogi said, "It's never over till it's over".