Ledecky breaks women's 400m free style record

American wunderkind Katie Ledecky smashed the Championships record of the women's 400m freestyle in the heats at the 17th FINA World Championships here on Sunday.

The five-time Olympic champion led the heats in 3:59.06, slicing 0.07 seconds off the previous Championships record, which was set up by her in Kazan two years ago.

Ledecky, 20, was unbeatable in the eight-lap event in last two edition of the World Championships and the 2016 Olympic Games. She set up the world record of 3:56.46 in Rio last year.

Ledecky's teammate Leah Smith qualified for the final in Sunday evening with the second fastest time of 4:02.00.

The 15-year-old Chinese rookie Li Bingjie also reached the final in 4:04.94.

Earlier, Chinese ace Sun Yang kicked off his defending campaign at the by qualifying for the men's 400m freestyle final in 3:44.55.

Sun's result ranked second in the heats as Austrian Felix Aubock took the top position in 3:44.19.

"I felt OK in the morning and I took the heats as a warm-up. I will try my best in the final but I did not set any goal for the evening," said Sun, who missed the Olympic title of the event last year in Rio as he was 0.13 seconds behind Australian Mack Horton.

Horton, ranking fifth in 3:45.60, trailed behind South Korean veteran Park Taehwan of South Korea who went through the heat in 3:45.57.

Three-time Olympic champion Hosszu Katinka received huge support from the home crowd. The 28-year-old Hungarian cruised into the semifinals of the women' s 200m individual medley event in 2:07.49, the fastest time in the heats.

London Olympic champion Ye Shiwen of China finished 14th in 2:12.48.

"I trained very well before the competition and I have high expectations about my results," said the 21-year-old, who suffered setbacks in recent years. "I' m a little disappointed for my timing in the heats. But I'm relaxed after the first swim and I will prepare for the upcoming events without anxiety. "

In other results, Olympic champion Sarah Sjostrom from Sweden led the women's 100m butterfly heats in 55.96 seconds. Olympic title holder Adam Peaty from Britain reached the semifinals of the men's 100m breaststroke in 58.21 seconds.