The duo had already topped the podium together in the duet technical routine in South Korea as well as collecting an individual world title each.

Kolesnichenko triumphed in the solo technical routine with Romashina taking top honours in the solo free routine to leave the pair as huge favourites going into today's competition at Yeomju Gymnasium.

They lived up to their billing with a score of 97.5000 after swimming a routine called "Spiders".

This saw them wear gold swimsuits featuring a black spider while their leg sequences and arm movements resembled the creatures.

Romashina has now won 21 world titles in her career with Kolesnichenko boasting 15 global golds.

The pair won this event together in 2013 and then each claimed it again with different partners in 2015 and 2017.

"This programme suits us," said Kolesnichenko.

"It's dynamic, emotional and extremely tricky. 

"We were surprised that we got only 9.5 for the difficulty in the prelims. 

"This is the most complicated programme we ever had. 

"Nine point eight in the final – that's what this routine is worth. 

"And of course we will work hard on the programme to improve, to be better at the Olympics. 

"As for now we can say that our vacation has started."

The podium was identical to the one for the duet technical routine as China's Huang Xuechen and Sun Wenyan claimed a second silver with a score of 95.7667.

Ukraine's Marta Fiedina and Anastasiya Savchuk made it two bronzes with a tally of 94.1000.

Russia have now won six of the seven artistic swimming categories contested in Gwangju and did not compete in the highlight routine final won by Ukraine.

Similar domination has been on display at the diving where China made it 10 gold medals out of 10 by winning the men's three metres springboard at Nambu University Municipal Aquatics Center.

They only kept their perfect run intact after a terrible mistake from Britain's Jack Laugher on his final dive, however, which saw the Olympic synchronised gold medallist slip from first to third.

Laugher was in control through the first five dives but his error allowed defending champion Xie Siyi to take gold on a score of 545.45.

Cao Yuan, who won the synchronised three metres springboard title in Gwangju with Xie, crept in to take silver on 517.85 as Laugher had to settle for bronze on 504.55.

Xie is now a four-time world champion while double Olympic champion Cao has three medals from South Korea after also winning the synchronised 10m platform with Chen Aisen.

In open water swimming the team event was held today with Germany winning gold.

Their quartet of Lea Boy, Sarah Köhler, Sören Meißner and Rob Muffels touched home in 53min 58.7sec in the five kilometre mixed relay format at Yeosu Expo Ocean Park.

Muffels, the individual 10km bronze medallist in Gwangju, took the anchor leg and added to the gold he won in the same event with Germany in 2015.

The Germans were 36 seconds behind the United States after Boyle and Koehler had completed their legs but the men moved them to the front of the pack.

Rachele Bruni, Giulia Gabbrielleschi, Domenico Acerenza and Gregorio Paltrinieri won silver for Italy in 53:58.9 as the US team of Haley Anderson, Jordan Wilimovsky, Ashley Twichell and Michael Brinegar slipped to bronze in 53:59.0.

"All of us are really happy taking down the win today," said Muffels.

"I think each of us did a really good job, it was a perfect strategy. 

"The conditions were quite good with some little waves, and they were not too big or challenging."

Day seven today also saw the conclusion of the group phase in the women's water polo tournament, with four table-toppers booking an automatic spot in the quarter-finals.

With the countries finishing second and third earning a play-off berth for the chance to also reach the last eight there was plenty to play for at Nambu University.

Reigning champions and current Olympic gold medallists United States topped the pile in Pool A with a third win from three, thrashing South Africa 26-1.

The Netherlands beat New Zealand 15-6 with the sides ending second and third respectively to book play-offs.

In Pool B, Russia saw off Hungary 12-7 to earn the automatic last eight place.

Canada thrashed hosts South Korea 22-2 to finish third behind the Hungarians.

Spain won Pool C with their third victory a 19-6 success over Cuba.

Greece beat Kazakhstan 13-7 as the sides finished second and third respectively.

In Pool D Italy maintained their perfect start to top the pile as they saw off China 14-6.

Australia ended second in front of the Chinese after their 9-7 win over Japan.

Play-off games will be played on Saturday (July 20) with Greece meeting China, Kazakhstan playing Australia, European champions Netherlands facing Canada and Hungary locking horns with New Zealand.

Tomorrow sees the conclusion of the open water swimming with gold medals on offer in the men's and women's 25km events.

The penultimate day of diving sees the women's three metres springboard final while the team free routine final will be held at the artistic swimming.

At the water polo arena the last matches of the men's pool phase will be held.

The Championships, the flagship event of the International Swimming Federation, will run until July 28.

Swimming action in the pool begins on Sunday (July 21).