Host Russia remained unbeaten in the synchronized swimming team free event after winning a fifth straight gold at the world championships July 31.
Russians have won the team free gold at every championship since the event was introduced in Melbourne in 2007.
The Russians claimed gold with a winning tally of 98.4667 points. China took silver with 96.1333 points and Japan claimed bronze with 93.9000 points.
Russia coach Tatyana Pokrovskaya said the home crowd lifted her team.
"With this kind of support it all worked out," she said. "The girls did great."
The Russians have now won seven of the eight synchronized swimming events in the host city of Kazan. The sole slip came when Christina Jones and Bill May of the United States won the mixed duet technical routine.
Three of Russia's veterans, Angelika Timanina, Alla Shishkina, and Aleksandra Patskevich, have won gold medals for the fourth consecutive championships, having been part of Russia's winning team from 2009, 2011 and 2013.