Perfectionism impacts how athletes evaluate their performance. However, little is known about how perfectionistic strivings and perfectionistic concerns interplay with athletes’ anticipated and actual performance in predicting mood after the competition. Thus, we conducted a study with amateur runners [n = 152, (72 female, 80 male); Mean±SD age = 34.71 ± 9.57] taking part in a competitive 10-kilometer street run. Perfectionism was measured before the run, while the measurement of mood was taken during the post-competition week. Mood was operationalized in the 3D model of mood, distinguishing between energetic arousal, tense arousal, and hedonic tone. Regression analysis showed that specific patterns of associations between perfectionism and goal-realization explain 17-21% of variance in the dimensions of mood. Higher pleasure after the run was predicted by lower perfectionistic concerns and better conversion of anticipated performance into actual performance. In predicting energy and tension, moderating effects of perfectionistic strivings, perfectionistic concerns, and conversion rate were observed. Johnson-Neyman technique revealed that only athletes low in perfectionistic concerns were able to benefit from lower tension when they met or exceeded their goals for the run. The higher athletes’ perfectionistic strivings and conversion rate the more pronounced effects we observed for affect-energization. Results support the idea of perfectionistic reactivity, where the negative consequences of perfectionism can be observed in a lack of positive reactions to positive events. We also suggest that such a response to meeting or exceeding one’s goal may contribute to the development of athlete burnout and hinder the development athlete engagement.