Sleptsova coped surprisingly quickly with senior biathlon, attaining several top-10 ranks before the start of the new year. Next, she finished the sprint at Oberhof, Germany as second, and repeated this result in the subsequent week at Ruhpolding. Later, after the disqualification of Kaisa Varis (Finland), she was awarded the victory of this competition. Sleptsova arrived at the 2008 World Championships in Östersund in good form, but an illness prevented her from demonstrating her maximum capability. However, she won the bronze medal in the mixed relay competition. At the end of the season, at Oslo-Holmenkollen, she achieved her first "real" victory, finally standing on top of the pedestal, and won the pursuit competition as well. She came up with similar results at the 2008 Russian Championships, winning three gold medals and the grand prize—a car. As of 2009, she has three world cup victories, excluding the one Varis retrieved after being cleared to compete again after IBU had broken test correction process.