As innovative entrepreneurship in China has increased, the transformation and upgrade of mature enterprises through secondary innovation has become a pressing issue. Using the concept of opportunity–resource integration as the research framework, this study examines the relationships between adaptive marketing capabilities (AMCs), opportunity exploitation, and sustainable innovation performance (SIP). The potential moderating effect of organizational legitimacy on these relationships is also investigated. Based on collected data from 163 high tech enterprises based in the Pearl River Delta region of China, the current study confirms that, first, both enterprise AMCs and opportunity exploitation significantly and positively affect sustainable innovation performance, and, second, that interaction between AMCs and opportunity exploitation significantly and positively affect SIP. The results also demonstrated that organizational legitimacy positively moderates not only the direct effects on SIP from both AMC and opportunity exploitation, but also the effect on SIP from the interaction between AMCs and opportunity exploitation.