World Cup points leaders Sarah Sjostrom (SWE) and Vladimir Morozov (RUS) both wrapped up two gold medals as Sjostrom stopped Hungarian Iron Lady Katinka Hosszu's clean sweep of the event after six stops and Morozov broke the World Cup record in the 50m freestyle. Local hero Joseph Schooling was upset and finished fourth in his favourite event, the 100m butterfly.
Fighting against jet lag, Rio Olympic champion Schooling was behind from the start and finished fourth in 51.05. Li Zhuhao (CHN), lift the title in 49.64 and Mattew Temple (AUS) 50.60 secured the silver medal in 50.60.
"Joseph just told me that he was sleepy since he just returned to Singapore, and of course he is not in his best form. He is a better and stronger swimmer than I am. I won the event just by chance. I still need to learn from Joseph, because last year he was the winner here and also champion at the Jakarta Asian Games in last September, "Li said.
In the women's 100m IM battle, Sjostrom showed her speed by winning 57.49, 0.07 faster than Hosszu. The Swedish star later claimed gold in the 50m free 23.21), while Ranomi Kromowidjojo (NED, 23.46 took silver and Pernille Blume (DEN, 23.67) bronze.
It is the first time Hosszu loses this particular race since 2014 - she won it 28 times in a row.
"It is the nature of the race. Anything can happen in a race. But I swam my fastest 200m fly of the season. That's OK. I think I am still not good at sprint event," said the Hungarian swimming star.
Hosszu was the winner in the 200m butterfly 2:02.86, beating Zhang Yufei (CHN, 2:03.93) and Alexandra Wenk (GER, 2:08.60).
World Cup men's point leader Vladimir Morozov (RUS) confirmed his domination in the 100m IM with a time of 50.31, 0.05 second away from his own World Record (50.26) which he tied in Tokyo last week. He later shattered the World Cup record in the 50m freestyle in 20.48, 0.01 faster than he did in Tokyo. Morozov made a clean sweep of the event in all the seven legs of World Cup this year.
In the men's 200m backstroke, China's World champion Xu Jiayu, took the led from the beginning to the end in Lane 8 and swam 1:48. 93, beating Mitchell Larkin of Australia who touched home in 1:49.28.
"I had a rusty morning heat performance and was almost out of the final. I felt upset for a while but fortunately I made the eight to the final. I could not let the winning opportunity running away from me anymore in the final. So I tried hard from the start to the end," said Xu, who smashed a new World Record in the 100m back in Tokyo last weekend in 48.88.
With the absence of Kirill Prigoda (RUS)l, Yan Zibei of China swam his personal best (56.34) and won the men's 100m breaststroke, beating Anton Chupkov (RUS) 56.69 and Ilya Shymanovich (BLR) 56.81,
Rio 2016 champion Mack Horton of Australia won a narrow victory in the men's 400m freestyle in 3:41.44 as he edged Velimir Stjepanovic of Serbia (3:41.52) and Blake Pieroni of the USA (3:41.94) in the last lap.
"I was expecting to swim a faster time but it was a close game especially in the last 50 meters. Three of us changed the lead in the first 350m and my win came from the strong finish," said Horton who claimed golds in Eindhoven, Budapest and Tokyo leg.
In other women's events, Reva Foos (GER) was the fastest in the 400m freestyle in 4:07.07, Kira Toussaint (NED) won the 50m backstroke 26.04 and Yuliya Efimova (RUS) ruled the 200m breaststroke 2:16.05.
Singapore is the seventh and last leg of the Swimming World Cup 2018.