Shortly after having arrived in Sparta, Kratos takes a secret path to the Temple of Ares, leading him through a dungeon. When accidentally releasing a Dissenter who was loyal to Ares, Kratos gives pursuit of him.
After searching for him through the jail, Kratos finally finds the loyalist in a circular open area of it, trying to pull a stuck lever, but before he can actually catch him, the Dissenter succeeds on pulling the lever, which not only closes the door to him, but also locks Kratos in the arena and releases the Piraeus Lion.
Kratos manages to fight the Lion and, after weakening it, he pulls himself to the Lion's neck, stabs it in the neck, making it roar in pain and slides down from it, gutting the lion, effectively killing it.
After defeating the Piraeus Lion, the door to the Dissenter opens, and Kratos continues to pursue him.
- The Piraeus Lion is actually a lion statue located in Piraeus (the ancient harbor of Athens).
- The player can allow the Piraeus Lion to fight Kratos again in the combat arena if it is purchased from the Temple of Zeus.
- Also, it's fight has only one phase, with only one quick time event. Both statements confirm the Piraeus Lion is a big and strong enemy rather than a boss in the game.
- This encounter is similar to the defeat of the Nemean Lion, which was killed by Hercules.