Ultimate Courage
Kid muscle has the perfect chance to escape from his match but sees that his friends who fought to protect him now were the ones who needed that protection.
Aired 19/06/2002EP 24 - Ultimate Courage

2002
Ultimate Muscle
Kid Muscle (or Mantaro for short) is a bumbling, gross, and wimpy sort-of person. Unfortunately, he has been summoned to protect the earth from the evil dMp, a band of cheating wrestlers from outer space. Luckily he's not undertaking this task alone. Kid Muscle must join the Muscle League, a group of wrestlers from outer space who are training themselves so they can defend the earth, and stop the dMp by achieving "Ultimate Muscle", a hidden power that makes Mantaro an almost unbeatable opponent.
(Source: Anime News Network)