GWANGJU, South Korea, July 21 (Xinhua) -- China's Olympic champion Sun Yang won his fourth consecutive world title in the men's 400m freestyle at the 18th World Championships here on Sunday.

Sun finished first in the 400m freestyle final, clocking three minutes and 42.44 seconds. It was his fourth straight gold medal of the FINA Worlds in the event since 2013.

Mack Horton of Australia touched home as runner-up in 3:43.17. Italy's Gabriele Detti timed in 3:43.23 for the bronze.

"I wanted to demonstrate myself, step onto the podium and watch China's national flag rising," said Sun. "It is a great honor for me."

"The training was really tiring. Perhaps only athletes know their own efforts behind the medals. As a senior athlete, I feel proud of myself as I keep fighting till now," said the triple Olympic champion.

Supported by the Chinese fans and applause from the spectators, Sun met expectations as he won the first gold medal on the opening day of swimming races at the worlds.

China sent a squad of 43 swimmers to the Championships, which offers a total of 42 swimming gold medals.