The Olympics are all about upsets - you just wish they don't happen to you and your nation. On Sunday night in London, one of the bigger ones in recent Olympic history occurred when the seemingly unbeatable Australian men's 4x100m freestyle relay team did not just fail to win gold, but left the pool without a medal of any colour.

Led by James Magnussen, the fastest man in water, the Australians were unbackable favourites to win the gold. Seemingly, the only matter up for debate was who would take out silver and bronze. But when the wall was touched at the end of eight laps by Australia's number four, James Roberts, his nation had no medal and his team's mettle was being questioned.

Shocker ... James Magnussen sits in disbelief after Australia finished outside the medals in the 4x100m relay. Credit:Steve Christo

It was clear very early - to those who knew what was supposed to happen - that Australia were in trouble. Magnussen led off, as he had when the team won the world title in Shanghai last year. But unlike in 2011, his pace was missing. It was as if he was swimming in board shorts.