By the end of 2003–04 season, however, Park had begun to adapt to the Netherlands, both on and off the field. In the 2004–05 season, the departure of Arjen Robben to Chelsea afforded Park more starting opportunities and he quickly proved his worth to the team. Along with Johann Vogel, DaMarcus Beasley and Dutchmen Mark van Bommel and Philip Cocu, Park formed the backbone of PSV's midfield play with his pace and passing. Having been a top contributor of goals and assists that season, the highlight of Park's PSV career came when he scored the first goal against Italian team Milan in the UEFA Champions League semi-finals. PSV went on to win the home leg 3–1, but their 2–0 loss during the away leg meant Milan advanced to the final.