This study explored the relationships among regulated learning, teaching presence and student engagement in blended learning. A two-level model was designed based on contextual factors (teaching presence) and individual factors (regulated learning), and experience sampling method was employed to collect intensive longitudinal data on 139 participants across three universities over 13 weeks in a blended course. Furthermore, multilevel regression analysis were conducted to examine the effects of teaching presence, self-regulated learning (SRL), co-regulated learning (CoRL) on intra- and interindividual variance in student engagement. The findings were as follows. (1) Perceived teacher support and instructional design fit had a significant positive effect on cognitive and emotional engagement and were crucial contextual factors that influenced intraindividual variance in learning engagement. (2) SRL and CoRL were copredictors of student engagement in blended learning. CoRL was more related to emotional engagement, while SRL was more related to cognitive engagement. (3) Modality had a significant effect on cognitive engagement but not on emotional engagement. (4) SRL and CoRL positively moderated the relationship between perceived teaching presence and cognitive engagement, while they negatively moderated the relationship between teacher support and emotional engagement, i.e., the relation between teacher support and emotional engagement was stronger in situations of low SRL or CoRL. Implications for teaching practice on blended learning were also discussed.