Russian Larisa Ilchenko battled past her rivals and fended off stinging jellyfish to win her second open water gold medal at the world swimming championships in Melbourne yesterday.

Her victory continued Russia's domination of the medals table with Olympic champions Anastasia Davydova and Anastasia Ermakova claiming the only other gold on offer yesterday with victory in the synchronised swimming technical duet final.

The 18-year-old Ilchenko added the 10km title to the 5km gold she won on Sunday in a sprint finish in waters off St Kilda in the southern suburbs of the city.

She won in two hours, three minutes 57.9 secs, touching out Britain's Cassandra Patten by just a second. Australia's Kate Brookes-Patterson won the bronze, repeating her third place from the 5km race.

"In the 5km nothing worried me, the conditions were perfect," Ilchenko said after her win.

"Today, I could hear the girls behind me screaming in the first lap. I expected it to be the same as the 5km, instead we're all walking around with spotty red faces."

The performance of Brookes-Patterson, who suffered more than most amid the jellyfish, was all the more remarkable given she spent the previous night struggling with a violent stomach upset.

"I was stung throughout the whole course and got smacked in the face a couple of times by huge, big jellyfish," she said.

"It didn't affect me too much. I realised everybody out there was getting stung."

Another gold

Davydova and Ermakova clinched victory and their third world title with a total of 98.833 points in the technical duet final at Rod Laver Arena. The duo had already won gold as part of the free routine combination team on Sunday.

They edged out Spain's Gemma Mengual Civil and Paola Tirados Sanchez into second with Japan's Saho Harada and Emiko Suzuki in third.

The Russians, who have won all three golds so far in the synchronised swimming, extended their lead at the top of the medals table to five golds to China's two.