Blended collaborative learning has emerged as an effective pedagogical model that integrates face-to-face and online learning environments, offering a dynamic platform for deep learning--characterized by critical thinking, knowledge synthesis, and application. However, existing research offers mixed findings on how blended collaborative learning promotes deep learning, with little focus on the integrated roles of learner engagement (LE), self-regulated learning (SRL), and group interaction (GI). This study addresses this gap by developing and testing a structural equation model to explore the interplay between LE, SRL, and GI and their collective impact on deep learning outcomes. A sample of 450 learners from higher education institutions participated in this study, which used validated survey instruments to assess these constructs. The findings indicate that LE significantly influences deep learning both directly and indirectly through SRL and GI. SRL and GI were also found to sequentially mediate the relationship between LE and deep learning, underscoring the importance of both individual self-regulation and collaborative interaction in fostering deep learning in blended collaborative learning environments. Additionally, gender differences in these relationships were explored, revealing subtle variations in learning dynamics between male and female learners. The study contributes to the theoretical understanding of blended learning environments and offers practical implications for designing educational frameworks that promote meaningful and lasting learning experiences.