BARCELONA -- Sun Yang became only the second man to defend his gold medal in the 800 meters men's freestyle at the FINA World Championships when he swam to a comfortable victory in the Palau St Jordi in Barcelona on Wednesday night.

Sun Yang finished with 7:41.36, which is the fastest time of 2013 and 2.27 seconds ahead of American Michael McBroom, who was second ahead of Canada's Ryan Cochrane.

China's Sun Yang celebrates after winning the men's 800m freestyle final during the World Swimming Championships at the Sant Jordi arena in Barcelona July 31, 2013.[Photo/Agencies]

The reigning world champions led the race at the first turn and looked comfortable in the following laps as he maintained a narrow lead over Jordan Harrison and Cochrane, although Harrison dropped away at around 400 meters as Connor Jaeger came into the reckoning.

By 550 meters McbBroom had also raced up the field and was in second, jut half a second behind the Chinese swimmer, before Sun Yang began to stretch his lead with around 150 meters remaining.

From leading the race by a question of centimeters, Sun suddenly led by meters as the closing three laps saw him give a demonstration of his quality.

China has now won three consecutive World Championship gold medals in this event, equaling the winning streak of the Australian team between 2001 to 2005.

Sun Yang has now won two gold medals in this World Championship meet in Barcelona as he won gold in the 400 meter freestyle on Sunday and he must be a favorite to complete a spectacular treble when he races in the 1,500 meters when the event closes on Aug 4.

China's Sun Yang reacts after receiving his gold medal at the men's 800m freestyle victory ceremony during the World Swimming Championships at the Sant Jordi arena in Barcelona, July 31, 2013. [Photo/Agencies]