This study aims to develop and understand what motivates university students to use asynchronous pre-class online video lectures (AOVL) for flipped classroom instruction. The study was conducted using a mixed-method research approach. A post-questionnaire survey and a focus group interview were employed in collecting qualitative data. A total of 31 respondents answered questionnaires and 10 respondents were interviewed in a focus group discussion. The quantitative result of the descriptive analysis indicates that students had positive perceptions in terms of intrinsic motivation and self-efficacy. Besides, Pearson r correlation analysis shows a strong correlation between the whole constructs (i.e., between perceived autonomy and competence = 0.618, autonomy and relatedness = 0.939, and competence and relatedness = 0.747). Consistently, the interview discussion also reveals that the use of AOVL had successfully promoted students' learning motivation both in and outside of the classroom. Data were analyzed using thematic analysis and three key themes were identified, namely; (a) students' mastery of content materials outside of the classroom (b) students' interaction with peers and instructor, and (c) students' learning autonomy. Conclusions from this study confirmed that the use of AOVL in the flip-class setting had successfully promoted students' intrinsic needs based on self-determination theory (SDT) perspectives, namely: perceived competence, relatedness, and autonomy.