Ginyu's Mistake! (ギニュー痛恨の大誤算！！, Ginyū Tsūkon no Dai-Gosan!!; lit. "Ginyu's Painful Miscalculation!!") is the two hundred eighty-ninth chapter of the Dragon Ball manga. This chapter's anime counterpart is the second half of the episode "Gohan, Defeat Your Dad!!".
The cover features a bruised and bloodied Captain Ginyu (in Goku's body) in the foreground with, in the background: Gohan, Krillin, Vegeta on the top, Goku (in Ginyu's body) in the middle, and Jeice on the bottom part of the background.
The chapter opens with Captain Ginyu (in Goku's body) bouncing off Frieza's spaceship after being knocked back. He angrily launches a ki blast at Gohan, who blocks the blast and then taunts Ginyu. Ginyu is confused as to why he cannot generate much power, and Krillin tells him that he does not know how to use Goku's body (as Goku had told him previously). Krillin tells him to give up. Ginyu refuses, and the two spar.
Meanwhile, Vegeta and Jeice are sparring. Jeice is puzzled as to how Vegeta could hide from his scouter, and Vegeta says that Jeice relies on it too much. He tells Jeice to read his power level now, and Jeice is stunned at the reading. Vegeta tells Jeice that he is getting close to becoming a Super Saiyan, which Jeice nervously scoffs at. Vegeta kicks Jeice and then strikes him in the chest, breaking his armor. He then obliterates Jeice with a Genocide Breaker, shocking all of the other combatants. Goku says that he has gone too far.
Vegeta then turns his attention to Ginyu, hitting him several times in succession before slamming him into the ground. Goku pleads with Vegeta not to kill Ginyu, but Vegeta charges down towards Ginyu, preparing to kill him. However, Ginyu laughs as he descends, and begins to execute the Body Change technique.