This paper presents research about the impact of a hybrid intercultural intervention sprint (HIIS) on the development of intercultural competencies in a group of Slovenian adult learners enrolled in a graduate-level MA business program. The study used a longitudinal design, with quantitative data collected both before N=40 and after N=36 the sprint. The HIIS consisted of innovative hybrid learning activities implemented in the form of inventive case-based learning, that took place January-February 2023. The study utilized the VALUE rubric, a survey instrument that measures attitudes, values, and knowledge related to intercultural competencies, with 14 items on a Likert scale. The longitudinal design of the study allowed for a comparison of intercultural competencies before and after the intervention. The results showed an increase in every category of intercultural competency, including attitudes (openness, curiosity), skills (communication, empathy), and knowledge (worldview and self-awareness): Attitudes increased from 30% to 41.7%, Skills increased from 22.55% to 41.7%, and Knowledge increased from 42.5% to 58.3%. This paper contributes to the existing literature on intercultural competency development and provides original insights with empirical data linked to the effectiveness of an innovative hybrid teaching approach in developing intercultural competencies in the Slovenian context.