Chinese swimmer Zhang Lin clocked a personal best at three minutes 43.35 seconds in Beijing on Saturday night and made to the men's 400 freestyle final as the second fastest seed.
US swimmer Larsen Jensen ranked first in the heats with a time of 3:43.10.
Zhang raced head-to-head against Park Taehwan, medal hope of South Korea, in the heat and was 0.25 seconds faster.
The first Chinese being allowed to train outside China, 20-year-old Zhang is considered one of China's hope of a male medal in the pool. These expectations stemmed from his impressive improvement after spending three months of training in Australia in 2008 with coach Denis Cotterell.
Cotterell has coached 16 swimmers to the Olympics, guided countless others to state and national titles. Four of his swimmers - Grant Hackett, Daniel Kowalski, Giaan Rooney and Andrew Baildon - have won Olympic medals.
Twice Olympic champion Hackett ranked fifth in the heats with a time of 3.44.03.
The final race will be held on Sunday morning in the Water Cube.
(Xinhua News Agency August 10, 2008)