[2][3] Detenyuk claimed her first title in the 200 m breaststroke at the 2008 FINA Youth World Swimming Championships in Monterrey, Mexico, demolishing a meet record of 2:25.19.

[5] At the 2008 Summer Olympics in Beijing, Detenyuk competed as a lone Russian swimmer in the women's 200 m breaststroke.

Swimming alongside Yefimova in heat four, Detenyuk tried to hold on with the top four leaders throughout the race, but faded down the stretch to take the seventh spot in 2:27.87.

Detenyuk missed the semifinals by 0.6-second margin, sharing a twentieth-place tie with Great Britain's Kirsty Balfour in the prelims.

[6] When Singapore hosted the inaugural 2010 Summer Youth Olympics in 2010, Detenyuk and her teammates Alexandra Papusha, Kristina Kochetkova, and Ekaterina Andreeva solidified their silver-medal finish in the girls' 4×100 m medley relay with a time of 4:11.07, trailing the victorious Aussie foursome by nearly two seconds.