Many South African university students either do not complete their degrees or take a prolonged time to meet the minimum degree requirements, with significant cost implications. Identifying malleable drivers of academic success is an important starting point in designing policies and programmes to improve student outcomes. To this end, we assess grit and intrinsic motivation as possible predictors of academic success, where motivation type is coded using text analysis of open-ended responses. We also investigate interactions between these traits. In line with existing literature, mostly in the United States and Canada, our results show that higher levels of grit are related to higher grades among Economic and Management Science students in a South African University. We further note intrinsic motivation as a significant predictor of grit levels. Our findings suggest that grade outcomes might be improved by interventions focusing on building grittiness in students.