An All-Out Kamehameha! Vegeta's Terrible Transformation! (激突かめはめ波！ベジータ執念の大変身, Gekitotsu Kamehameha! Bejīta Shūnen no Dai-henshin) is the fourteenth overall episode in the Dragon Ball Z Kai series. The episode first aired on July 5, 2009. Its original American air date was June 9, 2010. Its Dragon Ball Z counterpart is "Saiyan Sized Secret".
Goku powers up with the Kaio-ken x3 and attacks Vegeta with his increased power and speed, but is suffering extreme pain from using the Kaio-ken x3. After intense minutes of incredible battle, Vegeta is filled with rage as he is now realizing Goku's 24,000 power level exceeds his own 18,000, so he attempts to destroy Earth with his signature Galick Gun technique. Goku counters this with the Kamehameha combined with the Kaio-Ken x3's power.
After many minutes of an even power struggle, Goku overcomes Vegeta's Galick Gun by using the 4x Kaio-ken, putting all of his energy into the Kamehameha and blasting Vegeta into the atmosphere. Yajirobe, who had been hiding for the whole battle, comes out to congratulate Goku, but even a friendly slap from him gives Goku great pain. To Yajirobe's dismay, Goku reveals that Vegeta is still alive, prompting Yajirobe to flee once again.
Meanwhile, Vegeta manages to free himself from Goku's Kaio-ken Kamehameha. Infuriated at his performance against the low-class Saiyan Goku, Vegeta decides to transform into a Great Ape, which will increase his attributes tenfold. He starts searching for the full moon to transform into a Great Ape but much to his confusion, however, the moon is nowhere to be find.
Vegeta realizes that the moon has been destroyed to prevent he and Nappa from turning Great Ape and, thinking up a new plan, he returns to the battlefield. In front of Goku, he releases a Power Ball that replicates the moon's effects on a Saiyan. Although the Power Ball reduces his energy, it proves sufficient to transform Vegeta into a Great Ape. Krillin and Gohan notice the bright the Power Ball from afar, and decide to return to help Goku. Goku's only hope is the Spirit Bomb now. Can he get himself the time he needs? Or is the world doomed for good?