The present study compared virtual actors' and observers' perceptions of positive and negative psychological momentum (PM) and their responses to sudden interruptions of momentum. Participants with experience playing competitive table tennis imagined that they were playing a table tennis game (virtual actors), whereas participants who lacked experience playing competitive table tennis imagined that they were observing a table tennis game (observers). While viewing an audiovisual simulation of a table tennis match, participants were exposed to either an ascending (i.e., positive momentum) or descending (i.e., negative momentum) scoring sequence that was either suddenly interrupted or not interrupted at all. Participants' PM perceptions were measured at the conclusion of the simulation. Results indicated that observers' PM perceptions were lower than were virtual actors' following the negative momentum sequence. More generally, interrupting positive momentum lowered PM perceptions, whereas interrupting negative momentum increased PM perceptions. Implications for the study of PM in sport are discussed.