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Video - Park earns South Korea gold
South Korean teenager Park Tae-Hwan took Olympic gold in the men's 400m freestyle final in Beijing.
The 18-year-old tracked Australia's double Olympic champion Grant Hackett for the first 200m before pulling away.
He survived a late surge by China's Zhang Lin to secure his country's first Olympic swimming title. Larsen Jensen finished third in a new US record time.
Hackett, 28, twice an Olympic gold medallist in the 1500m, could only finish down in sixth place.
Park became South Korea's first swimming world champion when he won the 400m freestyle in Melbourne last year.
He burst onto the scene at the Asian Games in Doha in December 2006, where he won a 200m-400m-1500m freestyle treble.
His winning time of three minutes 41.86 seconds in Beijing on Sunday was a new Asian record.