Other source:
Gotenks and Super Buu begin to fight, and the collateral damage from the battle begins to destroy the lookout. Buu slams Gotenks down through the lookout itself. Down on earth, Gotenks tries another Super Ghost Kamikaze attack, but it once again fails. Buu lands a powerful hit on Gotenks that sends him flying back into the lookout. Buu then forms himself into a ball, and begins repeatedly shooting himself at the lookout until all that's left is rubble floating in the air. While still in a ball, Gotenks is able to trap him in a little sphere. He and Piccolo then play some volleyball with Buu, and Gotenks spikes him down to earth. Just when it seems like Buu is dead, a powerful blast of energy comes from the crater. Gotenks only has a few minutes until he separates.
