Top seed and defending champion Sun Yingsha of China survived a stern test from compatriot Kuai Man, battling to a 4-2 victory in the women's singles round of 16 at the ITTF Men's and Women's World Cup in China's Macao SAR (Special Administrative Region) on Thursday.

In a rematch of last year's title match, Sun overturned an early deficit and held her nerve in key moments to advance to the quarterfinals.

Kuai struck first, taking the opener 11-9, but Sun responded in dominant fashion, leveling the contest with an 11-4 second game. The momentum swung again in the third, as Kuai saved a game point and edged out the frame 12-10 to move ahead 2-1.

Under pressure, Sun delivered in the fourth. With the score knotted multiple times in the game, she slammed the door 12-10 to restore parity, before taking control in the fifth and pulling away to prevail 11-6.

The sixth game proved decisive. Trailing 7-2 and later 8-4, Sun mounted a comeback, drawing level multiple times before wrapping things up 13-11.

"It feels like fate meeting Kuai again here," Sun said. "She played an excellent match and her level has improved a lot in recent years."

In other action, World No. 2 Wang Manyu cruised into the quarterfinals with a 4-0 win over Japan's Mima Ito.

After falling behind 6-0 in the opening game, Wang rallied to triumph 11-9, a turning point that set the tone for the rest of the match. She followed up with 11-6, 11-5 and 11-3 wins to wrap up the contest in straight games.

"Winning that first game from 6-0 down was crucial," Wang said. "It gave me confidence and helped me settle into the match."

China's Wang Yidi also advanced, beating Japan's Miwa Harimoto 4-1. Wang claimed three tight games before dropping the fourth and closing out the procceedings in five.

Qin Yuxuan exited the tournament, however, following a 4-1 loss to Germany's Sabine Winter, who recovered from dropping the first game to take four in a row and put away the contest.