DBZ Episode 187
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
After Perfect Cell realized that he was no match for Super Saiyan 2 Son Gohan's awesome new powers, he decided to resort to using some of the Z Warriors' techniques, such as Kuririn's Destructo Disk and Piccolo Jr.'s Special Beam Cannon and Rapid Fire. After these attacks had failed, Cell tried to destroy Earth with a Kamehame-Ha. Gohan easily deflected the enormous energy wave with a Kamehame-Ha of his own, which swallowed Cell. Realizing that Cell was still alive and that he could regenerate, Piccolo told Son Goku to ask Gohan to finish Cell once and for all. Gohan refused and stated that he wanted Cell to suffer for what he had done to Earth and its inhabitants.
Cell then regenerated, and out of rage transformed into Power Weighted Perfect Cell. Gohan realized that Cell was too slow to catch him and pummeled the Artificial Human with two powerful kicks to the face and stomach. This forced Cell to actually regurgitate Artificial Human No. 18. With No. 18 no longer a part of his body, Cell transformed back into Semi-Perfect Cell.
 Major events
- Perfect Cell regurgitates Artificial Human No. 18.
- Super Saiyan 2 Son Gohan vs. Perfect Cell
- Super Saiyan 2 Son Gohan vs. Power Weighted Perfect Cell