At the 15th National Games, Shandong's Zhang Zhanshuo claimed a commanding victory in the men's 1500-meter freestyle. The 18-year-old had already secured wins in all freestyle individual events, including the 200, 400, and 800 meters, and now the 1500 meters, marking a stellar performance at these National Games. Starting from lane four, Zhang engaged in a tight battle with Zhejiang's Fei Liwei in lane five for the first 1000 meters, with the two exchanging the lead. In the final stretch, Zhang accelerated and touched the wall first with a time of 14 minutes 52.73 seconds. Fei Liwei earned the silver medal, while Shaanxi's Li Chengyu claimed bronze. The event took place in Shenzhen, adding another highlight to the city's hosting of the swimming competitions.

In the men's 400-meter individual medley, Zhejiang celebrated again as Wang Shun took the gold. The 31-year-old finished in 4 minutes 14.90 seconds, capturing his 19th career title at his fifth National Games appearance. After placing ninth in the morning heats and initially facing elimination, Wang was able to compete in the final due to teammate Zhao Liangzhou's withdrawal. The Olympic champion delivered a brilliant performance to secure his fourth consecutive title in the event.

In the women's 400-meter individual medley, Hebei's Yu Zidi finished first with a time of 4 minutes 34.33 seconds. The 13-year-old added a third gold to her collection at the 15th National Games, following victories in the 200-meter individual medley and the 4x200-meter freestyle relay. Henan's Chang Mohan and Hubei's Ke Wenxi completed the podium.

In the men's 50-meter backstroke final, Zhejiang veteran Xu Jiayu, who had broken the national record in the semifinals, claimed the gold medal with a time of 24.40 seconds. Hubei's Wang Zicheng took silver, while Shaanxi's Jiang Chenglin earned bronze. Xu Jiayu completed a clean sweep at the National Games, winning gold in the 50, 100, and 200-meter backstroke events, and finished the competition with a total of four gold medals.

In the women's 50-meter breaststroke, Tang Qianting dominated from start to finish. The Asian record holder, swimming from lane four, maintained her lead throughout the race and touched the wall at precisely 30 seconds to take the gold. Shanxi's Yang Chang claimed silver, and the Hong Kong SAR's Siobhan Haughey took bronze.

Right after the breaststroke final, the women's 50-meter freestyle kicked off. Having just won bronze, Siobhan Haughey of Hong Kong SAR returned to the starting block for another race. She faced stiff competition from Wu Qingfeng, the national youth record holder in lane seven, and Cheng Yujie, who had been fastest in the semifinals from lane four. In the end, Wu pulled ahead in the final meters and touched the wall first in 24.21 seconds, narrowly edging Cheng Yujie by just 0.02 seconds to claim gold.