This single-site case study aims to evaluate the effectiveness of the learning activities in a flipped EFL class so that critical pedagogical insights can be generated to enhance the design and implementation of flipped classrooms. Student engagement in learning activities was explored and examined to understand how the flipped classroom (FC) activities enhanced learning. A convergent parallel mixed-methods design with nested samples was adopted to collect data over a 15-week semester. Participants were from a flipped EFL class (n = 25) and a blended EFL class (n = 28). Data were collected from focus group discussions, participant observation, the learning management system (LMS) and iWrite. An adapted four-level Kirkpatrick Model was employed as the evaluation framework to explore student engagement in the
learning activities and measure the learning outcomes. Kahu’s engagement framework was employed to discuss the influencing factors. The findings of this project showed that the flipped design enhanced student performance in the learning process though there was no statistically significant difference in student final examination grades between the two classes. The findings further indicated that student engagement in learning activities was influenced by the interplay of teaching practices and student characteristics. Meanwhile, it was mediated by the assessment policy and practice and shaped by significant socio-cultural influences of China’s educational system and social conventions. Evidence-based reflections were then made to improve the design, implementation and evaluation of flipped classrooms. This project fills the current knowledge gap in the learning process of the flipping pedagogy and furthers our understanding of the mechanisms contributing to student engagement in flipped learning.