Olympics - South Africa's Chad Le Clos Upset Michael Phelps In 200 Metres Butterfly

South Africa's Chad le Clos upset Michael Phelps to win the 200 metres butterfly final at the London Olympics on Tuesday.

Phelps, who was bidding to became the first male swimmer to win the same individual event at three Olympics, led all the way but messed up his touch allowing le Clos to get his hands on the wall first in a time of one minute, 52.96 seconds.

Phelps took the silver medal in 1:53.01 while Japan's Takeshi Matsuda was third in 1:53.21.

The lone consolation for Phelps in suffering the shock defeat was that his second placing lifted his career tally to 18 medals, 14 gold, two silvers and two bronze, joining Soviet gymnast Larisa Latynina as the most decorated Olympian, though not for long.

Barring a calamity or a major upset, Phelps was poised to claim his 19th medal and take the outright record with the United States heavily favoured to win the 4x200 freestyle relay later on Tuesday.

The 200 butterfly is one of the most physically demanding events in swimming but is also Phelps' favourite and ironically, he is known as the best finisher in the business, famously winning the 100 butterfly final in 2004 and 2008 when he was behind.

He swam the 200 at the Sydney Olympics when he was just a 15-year-old and set his first world record and won his first world title in the exhausting four-lap race.

Only two swimmers have ever won the same individual event at three Olympics, Australia's Dawn Fraser, in 100 freestyle in 1956, 1960 and 1964, and Hungary's Krisztina Egerszegi in 200 backstroke in 1988, 1992 and 1996.

It is a feat that has eluded generations of the best male swimmers until Phelps, who had the chance of doing it in four different events in London.

He failed at his first attempt when he came fourth in the 400 individual medley but still has the 200 individual medley and 100 butterfly to come.