Cardiopulmonary bypass (CPB) is an essential component of many cardiac surgical procedures, but carries inherent risks related to its reliance on extracorporeal circulation and mechanical circuitry. Mechanical complications, though uncommon, can be rapidly life-threatening if not promptly recognized and managed. We report the case of a 68-year-old man with multivessel coronary artery disease (CAD) undergoing off-pump coronary artery bypass grafting (OPCABG) who required intraoperative conversion to CPB due to technical challenges. During the procedure, an acute rupture of the CPB circuit tubing resulted in rapid blood loss and hemodynamic instability. Immediate recognition by the anesthesia and perfusion teams allowed for prompt intervention, including circuit clamping, aggressive volume resuscitation, vasopressor support, calcium administration, and utilization of perioperative autologous cell salvage (PACS). The circuit disruption was controlled, and the patient was successfully stabilized and weaned from CPB with stable postoperative hemodynamics. This case highlights the importance of vigilance, early detection of circuit abnormalities, and coordinated multidisciplinary response in managing rare but critical CPB-related complications.