Who is Sentoumaru? Obviously Cracker fighting Luffy for 12 hours is better than anything Lucci ever did.
Fighting the version of Luffy that went on to get bitchslapped by Katakuri? The same Luffy whose CoA was so weak that he was injuring himself left and right just from clashing? Let's not forget that an even stronger version of Luffy got literally one-shot by base Kaido.