كتب : Sherif Tarek
The Asian side were dominant throughout the 90 minutes of the game while the 2004 European champions were completely out of form.
Lee Jung-Soo opened the scoring only after seven minutes when he connected with a free kick from point-blank range, thanks to Greece's sloppy defending.
The 30-year-old's goal is the fastest in his country's World Cup history.
Park Ji Sung doubled South Korea's lead eight minutes from the hour mark after stealing the ball from Loukas Vyntra and outrunning his marker to slot home with aplomb.
Greece's best chance fell to Theofanis Gekas who tried his luck from the edge of the area but his shot was parried away.
Another Group B match takes place later on Saturday between favorites Argentina and Nigeria.