Wow didn't know how different was the GX canon manga from the TV series.
Never thought Jaden (Judai) could lose to Chazz! :O :O :O ! - Anyway, it was a rematch, Judai won the first duel :)
To be fair, Chazz in the manga is overall not as important as in the anime. While in the anime he's practically one of the main casts, in the manga the only thing important about him is that he has "Light and Darkness Dragon", one of the two components of "Ma'at". You can replace his character in the manga with anyone else, and the plot wouldn't be affected at all.
In fact, Reggie McKenzie (a manga exclusive character that didn't appear until the second half of the plot) and Adrian Gecko (who in the anime are presented as minor character), are presented as the stronger opponents in the manga.