The interactions involved in postgraduate theses supervisions can be crucial to students' development of research skills, academic writing and their own sense of themselves as research writers. One relatively unexplored area of supervisory sessions, however, is the dynamic interplay of power in these interactions. This study examines advice-giving by two supervisors in supervision meetings with two L2 master’s students at an English-medium university. Drawing on observational data and detailed analysis of supervision transcripts, we show how supervisors and students co-construct their interactions through shifting power relations to shape the Literature Review Chapter. Exploring participants’ language choices in these encounters, we show how language helps to shape student and supervisor roles and enact power relations which in turn mediate students’ understandings of research knowledge and their positioning of themselves as writers. The findings suggest that power is reproduced as supervisory advice is accepted and challenged through student agency during the interaction. Power-over, power-gaining and power-maintaining interactions helped to reinforce sense-making in the encounters, develop students’ orientation to the task and increase their self-assured stance taking.