This study aimed to raise the achievement level of students in Integral Calculus using Direct Instruction with Razalas' Method of Grouping. The study employed qualitative and quantitative analysis relative to data generated by the Achievement Test and Math journal with follow-up interview. Within the framework of the limitations of the study, the Razalas' Method of Grouping revealed a significant increase on the gain scores between the two groups and a significant difference was obtained within and between groups (control and experimental). However, qualitative assessments further showed that the Razalas' Method of grouping creates and develops self-confidence, encourages effective communication and facilitates exchange of ideas towards a common goal. The students from both groups were in favor with the sequence of the presentation of the lesson, especially with the incentives given.