In series with good tournament arcs, the good guys suffer to get by even against 'filler' characters. An example from Yu Yu Hakusho:
[spoiler]In the fight against team Ichigaki, Yusuke has lost the ability to use spiritual attacks because he overdid it in the previous round. Hiei's right arm has been inutilized due to his use of the Jaou Ensatsu Kokuryuu Ha, and both him and Kurama have been held back from returning to the stadium due to a mecha Ichigaki sent after them.
Cue free-for-all fight with team Ichigaki up against team Urameshi. To top it off, the techniques used by the members of Ichigaki's team (a group of martial artists who sold themselves as guinea pigs so Ichigaki would heal their ailing master) are refined enough that for all effects and purposes, they are invisible. (So despite being 'filler' characters, they do have some degree of competence.) The team is controlled by a large, bulbous device on their backs, but forceful removal of the device equates death for them.
All the while, Ichigaki delights on how little chance they have to win without Hiei and Kurama on the team. Kuwabara senses their plight and tries to talk them back into humanity, which only manages to get him smacked around like a ragdoll.
The resolution of the fight itself involves Hiei and Kurama showing up with the ailing master, explaining that Ichigaki poisoned him to look like he was sick (which managed to reach out to the team and immobilize them long enough for the Masked Lady to KO them with some technique that sent the bulbous devices flying), and Yusuke getting pissed, recovering his spiritual power and proceeding to pound the crap outta Ichigaki.
Regardless of the outcome, this was easily one of the toughest fights the team had to endure up to that point, and if it weren't for the Masked Lady, they could have well lost the match.
Adding insult to injury, they had to proceed to the next match immediately afterwards. Thanks to trickery on the opposite team's part, Hiei and the Masked Lady get forcefully benched, and they have to face an elimination-style matchup with two people on five (with Kuwabara having suffered heavy damage on the previous match, he didn't count). [/spoiler]