This study investigates the effects of speed competition in classrooms on young pupils' learning outcomes. To examine how faster peers' speed affects slower pupils' speed and learning, we employ students' daily progress data in a self-learning programme at BRAC primary schools in Bangladesh. The programme's unique setting allows us to address the reflection problem reasonably well. While speed competition could generate negative consequences, our results show overall positive peer effects on problem-solving time and scores. The effects are stronger among peers with similar abilities, without negatively affecting others. Our results show efficiency gains from non-market competition in education and learning.