Chinese firms have been widely seen as imitative. This historical case study explores what organizational mechanisms allowed Tencent, a Chinese firm in the fast-changing instant messaging (IM) service sector, to achieve a new-to-the-world innovation with its WeChat smartphone app. Tracing the competitive dynamics in the Chinese IM sector from its inception, we found that Tencent was able to create the innovative WeChat product through a crisis-induced intrafirm coopetition dynamic that was embedded in variation-selection-retention evolutionary processes spanning the market, the firm, and the business unit levels. Building on the intrafirm coopetition and evolutionary literatures, the paper shows that three business units simultaneously competed and cooperated in developing alternative IM products while being exposed to market selection for survival. The coopetition dynamic took place in three key areas: technology, product promotion, and complementary assets of suppliers. The relative balance between competition and cooperation changed over time, and top management guidance and firm-level routines were essential in managing the challenges of coopetition within the firm.