Other source:
With Goku and Cell fully powered up, the battle begins, and as the match progresses, Cell realizes that they are very evenly matched, and so he resorts to trickery. First, he uses Tien's multi-form trick. Then he tries Piccolo's Special Beam Cannon and Frieza's final attack. Frustrated, he fires an incredibly powerful Kamehameha wave. Luckily, Goku is able to direct it away from the planet, and teleport back to the ring.
