GWANGJU, South Korea, July 24 -- China's Fu Yuanhui led the pool into women's 50m backstroke semifinals at the 18th FINA World Championships here on Wednesday.

Fu, who grabbed a 100m backstroke bronze medal in the 2016 Rio Olympic Games, finished first in 27.70 seconds in the 50m backstroke heats.

The Chinese swimmer, who got shockingly knocked out of the 100m backstroke trials on Monday, was followed by Etiene Medeiros of Brazil in 27.85 and Kira Toussaint of the Netherlands in 27.86 each in the 100m back heats.

Caeleb Dressel of the United States, who won seven titles in Budapest two years ago, qualified for semifinals in the men's 100m freestyle, hitting the wall first in 47.32 seconds.

China's He Junyi finished 14th in the 100m free preliminaries with a time of 48.76 seconds, managing to win a ticket for the semifinals later in the day.

In the men's 200m individual medley (IM) heats, Laszlo Cseh of Hungary punched the first ticket to the semifinals with a time of 1.57.79. China's Wang Shun timed 1:59.18, qualifying for the semifinals.

Hali Flickinger of the United States touched home first in the women's 200m butterfly heats, clocking 2:05.96. China's Zhu Jianming advanced into the semifinals with a time of 2:10.54.

The United States won the mixed 4x100m medley relay preliminaries, finishing in 3:41.23 to advance into the final in the evening.

The U.S. team was followed by Australia with a time of 3:42.22 and Russia in 3:43.30 respectively.