DB Chapter 386
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
"Trunks Surpasses His Father!" (父を超えた超トランクス！, Chichi o Koeta Sūpā Torankusu!; Literally meaning "Super Trunks Surpasses His Father!") is chapter 386 of the Dragon Ball manga.
Kuririn freaks out at how much Trunks is powering up, as Cell prepares to finish off Vegeta. Cell then notices Trunks, who has bulked up a lot now, and gets a very shocked look on his face. Kuririn tells Trunks his ki has gotten really fierce. Trunks tells Kuririn to take his dad to Muten Roshi's place, and when the timing is right, give him this senzu. Kuririn asks if he won't need the senzu himself, but Trunks says he won't, because he will win. Trunks lands, and Kuririn says he has awesome confidence. Cell thinks Trunks was hiding a lot of power, and Trunks says he'll kill Cell. They walk toward each other, until they're face to face.
Cell kicks at Trunks, but Trunks ducks it. Trunks punches at Cell, but Cell dodges it, then hits Trunks in the stomach and kicks him off. Kuririn is surprised, but Trunks looks at him and points to Vegeta. Trunks hops back to his feet as Cell rushes at him, and Cell punches him. But Trunks catches himself, and then holds off a bunch of strikes from Cell. Kuririn reaches Vegeta, as Cell hits Trunks with an elbow and sends him sliding across the ground. Kuririn puts Vegeta over his shoulder, and gives Trunks a thumbs up, then flies off. Trunks gets back to his feet, and smirks. Cell asks if he'll fight seriously now that Vegeta's out of the way, and Trunks is surprised he knew. Cell says of course he knew that, but he wasn't interested in Vegeta anymore. Now he's interested in Trunks' true power. Cell says he can show the strength of his perfect form now, too. Trunks says let's go, and starts powering up more.