While grit is considered essential to EFL learners as they navigate the challenges and setbacks of foreign language learning, it has been largely overlooked by EFL researchers. In this sequential mixed methods study with qualitative data and structural equation modeling (SEM), we examined the role of teacher confirmation and emotional support in predicting L2 grit among 309 low-proficiency Chinese EFL learners who were majoring in music, fine arts, and physical education at Chinese universities. Our results revealed positive correlations between teacher confirmation, emotional support, and L2 grit, with both teacher confirmation and emotional support significantly predicting L2 grit in our presumptive model. Qualitatively, we analyzed 22 participants’ responses to three open-ended questions from a semi-structured interview. Interviewees named a spectrum of interpersonal, learner, context, teacher, and task related factors they believed to be affecting their L2 grit. Among the interpersonal factors, teacher-student communication variables were most frequently named, echoing our quantitative findings. We discussed the limitations, pedagogical implications, and recommended future directions of this research.