Background: Introducing new technologies in education sparks debates, disrupting traditional practices, and requiring teacher adaptation. ChatGPT is an example. Research explores its benefits and concerns in education, with recommendations for classroom use. Nevertheless, limited evidence supports ChatGPT as a tool for supporting English as a Foreign Language (EFL) students' research competency. Moreover, while the literature primarily focuses on the perspectives of scholars and teachers, it is essential to incorporate students' viewpoints in order to maximize the potential of this technology. Objectives: The present study investigated EFL undergraduates' perceptions and practices of ChatGPT as a tool for promoting their research competency. Additionally, the study examined the potential influence of metacognitive awareness (MA) levels in this context. Methods: The study utilized a mixed-method research design, collecting quantitative and qualitative data from 27 EFL undergraduates (12 with low MA and 15 with high MA) over one semester. Data sources included a self-report questionnaire, self-study log, and semi-structured interviews. Results and conclusions: Quantitative analysis showed significant differences between low and high MA groups in their perceptions of ChatGPT (U = 37.500, Z = 2.570). Regression analysis revealed a positive correlation between MA scores and students' perceptions and practices of ChatGPT. Qualitative analysis revealed diverse perceptions and practices of ChatGPT between the high MA and low MA groups, showcasing behaviours ranging from replication to using ChatGPT as a thought-stimulating and supportive tool, accessing supplementary information, and seeking guidance. Key factors for effective ChatGPT use included prompt formulation, systematic thinking, self-regulation strategies, and trust in AI.