Russia coach Andrei Belofastov expects to encounter a different Spanish side when the teams meet in the women's Water Polo gold medal game on Saturday.
Russia eased to a 17-7 semi-final victory against Italy on Thursday, while Spain edged Greece 9-6 thanks to four goals from Alejandra Aznar Diez.
The results set up a rematch of the Group B clash won by Russia on Sunday.
"We beat Spain 12-8 but it was five days ago. Spain then beat a big Hungarian team and Italy. They are not the same team," said Belofastov.
Fresh from a day's rest having won their group and an automatic semi-final place, Russia raced into a 6-0 lead before overpowering their opponents.
"We were more mobile and faster," said Russia's four-goal hero Maria Bersneva.
Neither Greece nor Spain managed to create their usual attacking rhythm during the second semi-final, but Javier Aznar Fernandez's side made the necessary adjustments to reach the championship game.