Few academic studies have investigated how power and relationship commitment can promote service supply chain integration and create performance gains for firms in service supply chain. Based on resource-based view, transaction cost theory, and social network theory, we propose that relationship commitment is a significant mediator through which power influence the performance of service supply chain integration, and that competitor network competence is also a critical factor that facilitates this process. Empirical support for our argument was derived from data collected from 252 samples in service industry of South China. The empirical results suggest that both service integrators' power and service suppliers' relationship commitment affect the performance of service supply chain integration in a positive way, service suppliers' relationship commitment mediates the relationship between service integrators' power and service supply chain integration. Furthermore, competitor network competence moderated the relationship between service integrators' power and service suppliers' relationship commitment.