In the last several decades, and especially since the Chinese launching of the Belt and Road (BRI) initiative in 2013, the Chinese presence in Central Asia has intensified. Russia and Chinese leaders deny that there is any conflict of interests between them, while the standard narrative has been that the two states adhere to a functional division of tasks in which China concentrates on economic activity while Russia acts as the security guarantor for the region. This article argues that the professed equanimity between the Russian and Chinese leaderships masks the emergence of widening cracks in their relationship with regard to Central Asia. The convenient narrative of a functional division of tasks between the two states is called into question by China’s increasingly active presence in the military and security sector in the region, but China’s influence is growing throughout the Central Asian economic, political, and social order. China’s movement into Central Asia challenges Russia’s claim to act as an equal partner of China, as well as its pretensions to regional hegemony. This development reflects the widening disparity between the two states with respect to their power capabilities but it also exposes the interactions between Russia and China in Central Asia as the most vulnerable aspect of their relationship. In Central Asia, a defensive Russia encounters an ascendant China.