The Rh­(III)-catalyzed C–H functionalization and subsequent oxidative annulation between 5-aryl pyrazinones and internal alkynes are reported. This protocol provides facile access to a wide range of pyrazinone-linked naphthalenes via the C­(sp2)–H alkenylation and subsequent annulation. This transformation is characterized by mild conditions, simplicity, and excellent functional group compatibility. Notably, it is a first report of the utilization of pyrazinones as directing groups in C–H functionalization.