On the final day of the China Open Swimming Championships, Zhang Zhanshuo rose to the occasion, clinching the men's 800-meter freestyle title and once again asserting his dominance with a fourth individual gold medal in Shenzhen on Sunday.

Zhang entered the competition as one of the top contenders, alongside Germany's Lukas Märtens, who had surrendered his world record in the men's 400-meter freestyle while losing to Zhang in that event's tightly-contested final earlier at the Universiade Center.

The 800-meter final unfolded in gripping fashion, with Märtens holding a slender lead for the first 450 meters. Zhang showcased his tenacity, however, by overtaking him during the final 350 meters. He ultimately touched the wall first in 7:44.45, a new personal best. Zhang not only sealed the 800-meter title, but also became this edition's only quadruple gold medalist.

In the men's 200-meter individual medley, veteran swimmer Wang Shun demonstrated commendable resilience, leading from the start after a long hiatus, but ultimately finished second in 1:58.57, while Australia's William Petric snatched the title.

Other events that delivered thrilling performances included world record holder Regan Smith triumphing in the women's 100-meter backstroke. The American crossed the line under the 58-second mark for an impressive 26th time in her career.

Meanwhile, the women's 200-meter individual medley final saw Yu Zidi narrowly edge out Chinese compatriot Yu Yiting by just 0.08 seconds to clinch top honors, adding to the final day's excitement.