Chinese swimming ace Sun Yang failed to defend his 800m freestyle title as he finished fifth on Wednesday at the 17th FINA World Championships in Budapest, Hungary.

"I fought hard throughout the race, but I was unable to kick off the sprinting move, because I was quite tired," said Sun.

The three-time winner was restrained to the third and fourth place at turns after 400 meters, before he found it pretty hard to claw back in his familiar manner, and slid a place further behind Norway's Henrik Christiansen.

Sun finally clocked in with a time of 7:48.87 to finish fifth.

"My leg felt quite sore during the last several laps, and I found it hard to make my turnaround move," explains Sun, who already clinched gold medals in the 400m and 200m freestyle events in Budapest.

"My opponents probably thought that I might fail on my sprint today, so they just sped up from the start, and I had to follow them. Then after 600 meters, I felt very bad about my move," he added.

Italy's Gabriele Detti made a decisive sprint in the last 50 meters to take the gold with a time of 7:40.77, a new European record.

Italy's Gabriele Detti wins the men's 800m freestyle final at the 2017 FINA World Championships. / AFP Photo

Wojciech Wojdak of Poland finished second at 7:41.73. Italian Gregorio Paltrinieri, a 1500m freestyle Olympic gold medalist in Rio, placed third at 7:42.44.

Sun will also compete in the 1500m freestyle event in the Hungarian capital.

(Source: Xinhua)