Hosts Uzbekistan, Mexico and Kazakhstan all claimed gold medals on the opening day of the final International Swimming Federation Artistic Swimming World Series event of the season in Tashkent.
Action is due to take place over three days at the Sahovat Swimming Center in the Uzbek capital.
The host nation enjoyed victory in the team technical event, although they only had to win a two-horse race.
Uzbekistan won with 75.9284 points to beat Slovakia's haul of 72.5023 points.
Karen Faride Achach Ramírez and Nuria Lindón Diosdado García of Mexico lived up to their favourites' tag with a comfortable victory in the duet technical final
They scored 83.8356 to beat the haul of 76.4281 achieved by Jennifer Russanova and Yana Degtyareva of Kazakhstan.
Germany's Mariene Bojer and Daniela Reinhardt took bronze with 76.3017.
Kazakhstan's Sofiya Lyakh and Olzhas Makhanbetyarov won mixed duet technical honours with 69.1749 points.
Uzbekistan's Dinara Ibragimova and Vyatcheslav Rudnev took silver with 68.8465 in another two-team competition.