Chen Ruolin and Liu Huixia maintained China's 100 per cent Olympic record in the women's synchronised 10-metre diving event on Tuesday, in an unusually green pool, and kept alive hopes of a clean sweep.
Ruolin and Liu posted 354.0 points from the five rounds for an undisputed victory, the third in three diving events completed so far.
Cheong Jun Hoong and Pamg Pandelela Rinong got silver for Malaysia with 344.34 points and the bronze went to the Canadian pair of Meaghan Benfeito and Roseline Filion with 336.18 points.
China have won all four women's diving events at the past two Games and in Rio are bidding to sweep all eight events in the sport overall. So far they have won two on the women's side and one for men.
Chen meanwhile won her third straight gold in the event and with five golds overall equalled the record of compatriot Wu Minxia.
"In the past four years there have been some injuries and also I had some prolonged recoveries. When you're injured you cannot participate in your normal training and your training will fall behind schedule. And that is a huge challenge," said Chen who was named "absolutely awesome" by her partner Liu.
While China's win was nothing unusual, the pool colour was in a strange change from blue to green - forming a stark contrast to the adjacant water polo pool which remained blue.
Britain's Tom Daley, who earned bronze in the men's synchro platform the previous day, tweeted a photo of the pools as he wondred "Ermmm...what happened?!"
A filter problem was suspected though organizing committee spokesman Mario Andrada said "we don't know exactly what happened."
Pamg shrugged off the issue, saying: "I think the water is normal for an outdoor pool, so it's not a big deal for us as long as it doesn't affect our performance."
Benfeito said the Canadians had to control themselves when they got ready for their first jump.
"It was weird. I remember getting up on the tower and (Filion) didn't want to laugh because it's not really the blue that we're used to, but it helped. It's not the same colour as the sky so that was really on our side today.
"It's water. We know that it's water down there. The fact that it was green actually helped. The only thing we said is, 'Don't open your mouth in the water'. Just in case."