Lee Chun Soo was carrying a cold during Saturday's A3 Champions Cup game but the striker still managed to score a brilliant second-half hat trick in Ulsan Hyundai's 6-0 win over Gamba Osaka.
Brazilian Leandro also scored twice and Kim Young Sam once as the South Korean champions ran riot against a tired-looking Gamba side at Tokyo's National Stadium.
Both teams are now on three points each in the four-team tournament after Gamba beat Chinese side Dalian Shide 3-2 in their first game and Ulsan lost 3-2 to JEF United Chiba.