Yulia Efimova scored a victory over rival Lilly King to take gold in the women's 200 metre breaststroke at the FINA World Championships.
The pair have been embroiled in a bitter rivalry dating back to last year's Rio Olympics, with King speaking out over Efimova being allowed to compete at elite level despite having been caught using banned substances.
American King triumphed over Efimova in the 100m earlier this week in Budapest in a repeat of their infamous battle in Brazil, but it was the Russian that was top of the podium on this occasion.
Efimova's time of two minutes and 19.64 seconds was enough for her to repeat her 2013 gold medal success in Barcelona, while Bethany Galat (USA) and Shi Jinglin (China) completed the podium and King had to settle for fourth.
It was part of a fine night of success for Russia, who claimed three of the five swimming gold medals on offer - including Anton Chupkov breaking the championship record to win the men's 200m breaststroke.
In the women's 100m freestyle, Sarah Sjostrom was unable to back up her record-breaking effort in the heats as she was beaten to first place by American rival and Olympic champion Simone Manuel.