Like coaches and athletes, referees and officiating crews are under pressure to perform well in competitive events. Drawing from a mixed-methods study that assessed emotions and emotion regulation strategies of 19 referees officiating at a Lacrosse World Championship, we explored how referees managed their own emotions as well as the emotions of coaches, athletes, and other officials. We also assessed referees' emotional states and satisfaction with their emotion regulation abilities throughout the course of the tournament, as well as participants' self-rated performance. Results indicated that emotions fluctuated throughout the tournament as referees encountered intrapersonal and interpersonal emotion-eliciting events. Attempts to regulate these emotions are situated within a socio-functional approach to emotions drawing upon the Van Kleef (2009) Emotions As Social Information (EASI) model to explain the processes of interpersonal emotion regulation. Factors that potentially moderate strategy effectiveness are also presented.