The study aimed to investigate the impact of transition to university-level mathematics, specifically in a first-year Discrete Mathematics course, by comparing the performance of domestic and international students, as well as students enrolled in different teaching periods (first vs. second term). Contrary to expectations, students enrolled in the first term performed better than those in the second term, suggesting that delayed enrolment does not provide an advantage in adapting to discrete mathematics. There was a significant difference in performance between domestic and international students, with domestic students outperforming international students in both terms. The study found no significant interaction between the term of enrolment and student origin (domestic/international). It is suggested that the performance gap between domestic and international students may be attributed to the ‘first-time phenomenon’ - the shock of experiencing difficulty with mathematics among previously high-performing students. This effect might be more pronounced for international students due to their typically strong preparation in core mathematics and the added pressures of studying abroad. The evidence indicates that the unfamiliarity of discrete mathematics content and the high level of justification required in problem-solving may contribute to the observed differences, particularly affecting international students’ confidence and willingness to seek help. The study highlights the need for further qualitative research to better understand students’ perceptions of their difficulties and the strategies they adopt to overcome challenges in discrete mathematics.