Natural gas markets have been traditionally territorialized within the nation-state apparatus. However, since the early 1980s, the territoriality of these markets has been evolving through liberalization, cross-border market integration, and globalization in the form of liquefied natural gas (LNG) trade. These dynamics have materialized unevenly across the global economy. While natural gas market liberalization has been implemented in the United States and Europe, natural gas markets in most Asian countries continue to be firmly controlled by regulated or state-owned natural gas monopolies. This is the case in Thailand, where despite multiple reform efforts since the 1990's, the partially privatized, state-owned natural gas company, PTT Public Company Limited, continues to hold a lucrative monopoly over markets in Thailand. In this article, I explain why natural gas market liberalization in Thailand has failed to materialize by drawing upon an analytical toolkit that includes both territorial and topological notions of power. In doing so, I aim to contribute to geographical studies of energy by demonstrating the different arrangements by which powerful actors may reproduce their authority over energy systems. PTT has historically maintained its reach over natural gas markets through the exclusive yet contested authority of the Thai-state over domestic natural gas resources and infrastructure. However, more recently, this authority has been transformed by LNG imports and the introduction of natural gas sector reforms in Thailand. Nevertheless, I find that PTT continues to reproduce its monopoly in gas markets by quietly working through regulations, contracts, and pricing regimes.