In 2005, Jerry Yang, co-founder of US Internet giant Yahoo!, bought shares in Chinese e-commerce company Alibaba Group for USD 1 billion. The two sides hoped to combine Alibaba’s Chinese market experience with Yahoo’s search technology to become a dominant player in China’s e-commerce market. Since then, Alibaba grew rapidly while Yahoo shrunk, leading Alibaba Group’s founder Jack Ma, to become dissatisfied with Yahoo’s influence within the Group. In the first half of 2011, Alibaba Group and Yahoo! had an open dispute over ownership of Alipay. This case looks at how their cooperation turned sour.