The Russians dominated both rounds of the competition in Rio, earning the highest scores in both areas to retain the London 2012 title.

They scored 96.4577 in the technical round before a free routine score of 98.5333 gave them a total of 194.9910.

Ishchenko and Romashina became the second Russian pair to repeat duo success, as countrywomen Anastasia Ermakova and Anastasia Davydova won at both Athens 2004 and Beijing 2008.

"Psychologically it is very hard because we understand that a victory is always expected from us synchronised swimmers," said Ishchenko.

"We set the bar so high already and obviously we cannot drop it. 

"There is great attention put on us. 

"We are always being watched so we have to be three heads higher than the rest of the field.

"Each year is not easy, and this one was not easy because we were working a lot. 

"There is a great responsibility placed on us, and our competitors are very strong."

In second place were the Chinese team of Huang Xuechen and Sun Wenyan with a total score of 192.3688 which was enough to secure the silver medal, securing the best-ever finish for China in duet at the Olympics. 

Japan missed the duet podium in 2012, but Yukiko Inui and Risako Mitsui earned 188.0547 for bronze medals.

This was Japan’s seventh medal in this event, out of the eight times it has been on the Olympic programme.

The only missed out on a medal four years ago at London 2012 and the seven medals won by Japan is more than any other National Olympic Committee has won in this event.