Until now, the Russian company Gazprom has been the dominant gas supplier of the Balkan countries. Most of the projects for new gas pipelines in the Balkans have failed or have become stagnant in recent years for two main reasons: lack of gas to feed them (Nabucco, ITGI, Bulgaria’s “Balkan” gas hub), or an adverse geopolitical environment (South Stream, Turkish Stream). But it is already clear that Azerbaijani gas from the Shah Deniz field will reach Balkans through the Southern Gas Corridor. This article examines the Balkan routes of the Azerbaijani gas, and answers the question of how this new source of gas will influence the energy geopolitics of Turkey, Bulgaria, and Greece. The conclusion is that the gas from Shah Deniz will trace out a new energy corridor through the southern part of the Balkans. Pursuant to this, an additional gas supply infrastructure could be built around this corridor – LNG terminals, interconnectors and new pipelines to bring gas from Turkmenistan, Iraq, or from the Eastern Mediterranean to Europe. Azerbaijani gas will, to a significant degree, act as a game changer in the Balkan energy geopolitics, although Gazprom will retain its role as a main supplier for the region.