Background: Appraisals of control and value are proposed as proximal antecedents of achievement emotions, which, in turn, predict achievement. Relatively few studies have investigated how control and value may interact to determine achievement emotions, or subsequent achievement mediated by emotions. Aim: To examine whether control, value, and their interaction predicted mathematics test score directly, and indirectly, mediated by three salient achievement emotions: enjoyment, boredom, and anxiety. Method: Data were collected from 1,298 primary schoolchildren. Participants completed self-report measures of control, value (i.e., intrinsic, attainment, and utility), and achievement emotions (i.e., enjoyment, boredom, and anxiety), in the context of mathematics. Participants then undertook a curriculum-based mathematics test in class. Results: Higher control and value were related to a higher mathematics test score directly, and indirectly, mediated via higher enjoyment and lower anxiety. The interaction of control and intrinsic value predicted mathematics test score directly, and indirectly, mediated via enjoyment. Conclusion: Intrinsic value amplified the direct positive relation between control and mathematics test score. Intrinsic value also protected mathematics test scores at lower levels of control indirectly, through higher enjoyment. Helping students to maximize control and value will be beneficial for their learning experience and outcomes.