There are different functions a mentor can perform for a mentee. The literature on mentoring creativity reveals many proposed functions for mentees' creativity like advancing relevant skills, role-modeling, career-related and psychosocial support. However, only qualitative studies actually investigated how different functions each contribute each specifically to mentees' creativity. Accordingly, research broadly discusses "mentoring works", but no quantitative study looked further into mentoring functions for the field of creativity. The association between these functions and creativity was investigated in an online study with 161 participants including artists, writers, and scientists using existing items from two mentoring scales. Additionally, we measured ability to be autonomously creative with a self-developed scale. We first performed a factor analysis on mentoring items. Several distinguishable functions emerged: Advancing domain relevant skills, role-modeling, interpersonal tensions, career-related and psychosocial support. Creative autonomy was related to psychosocial support. Second, we investigated whether different mentoring functions are associated with everyday creativity and creative achievement, that is, checked for concurrent validity of interpretation. Surprisingly, functions proposed in the mentoring literature could not predict creative outcomes, but interpersonal tensions did for creative achievement. We hypothesize results could be explained by a demanding achievement-orientation of mentors; or arguing about ideas in non-hierarchical relationships.