Nine national records and one Asian record fell at the Chinese National Swimming Championships which ended on Monday while star swimmer Sun Yang dominated freestyle events by sweeping five individual titles.
Sun Yang, the world record holder of the 1,500m event, finished the 30-lap final in 15 minutes and 4.15 seconds.
After almost eight months absent from competition, the 25-year-old triple Olympic champion took part in the 100m, 200m, 400m, 800m and 1,500m events at Qingdao and collected all the five golds in eight days.
His winning marks in the 200m and 400m freestyle are both placed in the top position of this year's world rankings so far.
"I did feel tired. My back and shoulders hurt and I felt uncomfortable after swimming 500 meters this evening," said Sun, who had never competed in such a tense schedule.
"But it's a good practice for me and I'm happy that I manage to fulfill the plan. As the captain of the Chinese swimming team, I hope I could be a model for the younger swimmers."
Xu Jiayu, Sun's teammate in both national and provincial squads grabbed his fourth gold medal by winning the 50m backstroke in 24.48 seconds.
In the semifinals on Sunday, the 21-year-old finished the race first in 24.42 seconds, slicing 0.16 seconds off the previous national record.
As the Olympic silver medalist, Xu broke the Asian record of the men's 100m backstroke on Wednesday and his result of 51.86 seconds is only 0.01 second shy of the world record. Then he took his own national record of the 200m backstroke down by 0.76 seconds to one minute and 54.03 seconds.
"My upper body strength has been enhanced and I'm happy that I improved my personal bests this time," said Xu, who also brought home a 4x200m freestyle relay title. "I will be more confident in the future."
Wang Shun led the men's 400m individual medley final in four minutes and 12.65 seconds, but the Rio Olympic bronze medalist achieved more in the 200m medley event as he clinched the title by breaking the national record in one minute and 56.16 seconds on Friday.
London Olympic champion Ye Shiwen failed to reach the podium of the women's 400m individual medley while Zhou Min claimed the gold medal in four minutes and 37.65 seconds.
In other finals, Suo Ran won the women's 50m breaststroke in 31.30 seconds. Liu Xiang took victory in the women's freestyle in 24.81 seconds. Team Jiangsu led the women's 4x100m medley relay in four minutes and 3.52 seconds while the men' s team from Zhejiang won the equivalent event in three minutes and 35.71 seconds.
In last week's competition, Olympic bronze medalist Fu Yuanhui rewrote the national record of the women' s backstroke.
The 21-year-old Yan Zibei took down the national records of the men's 50m and 100m breaststroke.
Qin Haiyang, who turns 18 next month, surprisingly clinched the title of the 200m breaststroke with a national record breaking time of two minutes and 8.71 seconds. His winning mark is also the new world junior record.
The 18-year-old Li Zhuhao snapped three butterfly titles and broke the national record of the 50m race.