GALLERY: London Olympics Opening Ceremony
Meanwhile South Korea's Park Tae-hwan was disqualified from the 400 metres freestyle on Saturday, ruining his chances of defending his Olympic gold medal.
The 22-year-old, a superstar in his homeland after winning the 400m gold in Beijing four years ago, said he was disqualified for a false start when he left the blocks a fraction too early.
With Park out of contention, China's Sun Yang is now the overwhelming favourite to win the gold in the final later on Saturday.
He set the fastest overall time of three minutes 45.07 seconds, just ahead of American Peter Vanderkaay (3:45.80).
Germany's Paul Biedermann, the world record holder for the event, missed out on the final after finishing 12th overall in 3:48.50.