In his first "Clássico" against Porto, he followed on to score for Benfica with a header following a corner kick, the second goal he has scored for Benfica in the league in just a few matches. Katsouranis quickly became a key player for Benfica, scoring some important goals and also captaining the team on a few occasions. He proved to be one of the most important imports into the 2006–07 Portuguese Liga, playing in 29 league matches and scoring six goals.