Mass gatherings at sporting events pose critical risk for crowd safety, especially in venues with limited history of hosting high-demand events or insufficient data to inform evidence-based interventions. Ahead of the UEFA Europa League (UEL) Final 2024–2025, San Mamés Stadium implemented staged access protocols across league matches. These real-world experiences provide a timely case study on crowd management strategies and operational planning in urban environments. This work presents a simulation-based study of the pedestrian ingress dynamics during fan entry to the stadium under high-attendance settings. The agent-based modeling framework integrates a Social Force Model that considers the pedestrian’s limited visual range, queuing behavior, and where path-finding is computed from the numerical solution of the Laplace equation. Using empirical data of the geometrical constraints of the stadium and its surrounding areas and timestamped turnstile access records from pre-final league matches, the model reproduces the pedestrian flow under every access protocol implemented during the tournament. Quantitative analysis of ingress efficiency, access rates, and pedestrian flow patterns reveals specific stadium-adjacent zones susceptible to undesired counterflow and overcrowding. Simulations indicate that the suggested access guidelines can streamline crowd movement and lower density levels by roughly 20%, while delaying individual screening at the fenced security perimeter by 2.5 s can decrease the maximum average local density by nearly 80%. These findings emphasize the role of computational modeling as a decision-support tool, allowing the evaluation of alternative crowd management strategies before their implementation in real-world events.