This study is an autoethnographic reflection on power and expertise in an evolving student/staff partnership. The partnership was initiated as pedagogical co-design in the development and implementation of a peer-assisted learning programme. Through a process of critical reflection that linked our partnership experience with themes from relevant literature, we (the staff and student authors) became co-researchers of our practice. The evolution of the partnership provided a unique perspective from which to compare our experiences of power and expertise across both contexts. We characterised our pedagogical co-design partnership as a shift from the more traditional 'power over' model of delivery towards 'power to empower' where both student and staff partners had agency and voice. Key to this important transition was a shared philosophy of student-centred teaching. As the partnership transformed from co-teaching to co-researching we needed to re-negotiate power dynamics; while our different pathways had converged on a common view of student-centred learning, our research expertise remained disparate. We were able to negotiate this challenge by drawing on our existing relationship based on respect, reciprocity and responsibility, reinforcing views of partnership that value equality of opportunity and a focus on learning and process, rather than equality of contributions and outcomes.