Saitama vs. Suiryu

You are not the only one doing what he wants to do. I'll give you some advice too. If your goal is to have fun, then it would be best if you don't become any stronger than you are now. Saitama vs. Suiryu was the Super Fight Tournament match between Saitama and Suiryu.

Prelude
Saitama (disguised as Charanko) faces Suiryu in the finals of the Super Fight Tournament. As soon as the match starts, Suiryu delivers fast, powerful blows towards Saitama, but always stops mid-way. Saitama's only reactions to these attacks are stopping his wig from being blown away by the dangerous wind pressure from Suiryu's blows, or slightly moving away. Being unable to keep up with Suiryu's fast moves, and seeing Saitama with both hands on his head, the Super Fight Announcer assumes Saitama is too shocked by Suiryu's moves to react.

Hearing this, Suiryu sighs in annoyance as he states that they had no idea what was really happening. He reveals that he never had any intention to hit Saitama at all, and was merely sizing him up. The lack of reaction from Suiryu's attacks made him realize that Saitama was strong, and that he was also trying to figure out what the martial artist was capable of. He also says he could see in Saitama's eyes that he isn't after fame or prestige, but rather a fun battle, to which Saitama agrees. Acknowledging Saitama's strength, Suiryu tells him he is strong too, and that he entered the tournament because he wanted the prize money, but deep down he also wanted to fight strong opponents. He explains that he became strong to the point of being bored, but he also says that being strong was fun, since he was guaranteed to have an easy, carefree life, and that whenever he got the chance to fight strong people, he got excited, looking up to find a thrill to satisfy himself.

Saitama deems Suiryu as a positive guy, and tells him he entered the tournament so that he could experience real martial arts, revealing he also craved for strong opponents. However, he also states that he was rather disappointed, since all of his matches ended with a single blow, and that maybe he just wasted his time entering the tournament. But seeing the huge cheers and Suiryu's confidence, Saitama realizes that he might have finally found a worthy opponent.

Both then make a deal: Suiryu would give Saitama the martial arts experience he was looking for, and Saitama would do his best too so that Suiryu could have a fun time. With that settled, the real fight begins.

Battle
Suiryu takes the initiative and strikes Saitama with a kick, several times faster and stronger than the ones he used before. It nearly sends Saitama out of the ring, much to everyone's surprise. Suiryu keeps attacking Saitama with kicks, while the latter just dodges or protects his wig. Eventually, one of Suiryu's blows send Saitama upwards, and with amazing speed and technique, Suiryu jumps and kicks Saitama down still in mid-air. Saitama crashes into the ring, opening a huge hole in it, and before he gets any time to recover, Suiryu lands on his back and knees Saitama's head into the ground.

Astounded by that demonstration, everyone believes Saitama is dead after those attacks. Even Suiryu himself thinks the match is over, and states with disappointment that maybe he should have held back. To everyone's surprise, Saitama casually gets up, and is relieved his wig is still intact. While they re-engage in their fight, the other contestants watch the battle in awe, and Sour Face even states that if "Charanko" kept holding up like that, he could end up winning. The other fighters disagree, as Max and Sneck realize that Suiryu had only been using leg techniques at that point, and that he was most likely doing so to limit his combat options for his own amusement. As Sneck claims Suiryu's cocky attitude didn't change, they conclude Suiryu is still hiding his true power. Suiryu himself confirms their theory, stating that since Saitama had beaten all of his opponents with punches, he'd fight with kicks because it'd be more fun that way.

Eventually, Suiryu notices how Saitama keeps avoiding his attacks and how his defense was rock-solid on the cranial area, even though it gave away everything else. Unaware that Saitama is merely protecting his wig, Suiryu questions him about his daily routine, to which Saitama accidentally reveals that he kills monsters. Suiryu doesn't fail to notice that, which leads to Saitama making up excuses, saying he wanted to be a hero someday (as Charanko).

Suiryu then reveals his complete distaste for heroes, claiming "hero" is just a nice name, and that they are all condescending people who preach their justice and expect something in return from their good deeds. He also says that it's pointless to rely on them, since no matter their level, they could never save the world from a crisis. To Suiryu, everything that defines a hero is unnecessary for the easy life he seeks, and that they are the very foundation of boredom. Much to everyone's surprise, Saitama doesn't dodge or block Suiryu's next kick, which leads to his wig being blown away. Clearly displeased with Suiryu's rants, Saitama finally decides to attack, but stops mid-way before he could end the battle with a single punch again. The wind pressure from his blow is so strong that Suiryu's clothes are ripped as he stares in shock at Saitama.

Saitama is immediately disqualified when the staff realize he was wearing a wig the whole time, claiming that since the last tournament (with Garou posing as Wolfman), fraud is not tolerated. Suiryu, however, doesn't accept winning like this and, after ripping the remnants of his gi, starts fighting seriously. Enraged, Suiryu's blows become strong enough to split the ring in half, and he even manages to lift half of it with a mere step. He tells Saitama losing wasn't fun for him, and with that, Suiryu starts delivering blows with such ferocity that the security staff get too scared to stop the fight.

When he notices his attacks don't seem to affect Saitama, Suiryu does a powerful step-in, shattering one half of the ring into pieces and using it's momentum to strike Saitama full force, ripping his arm-band as a result. Saitama, who doesn't show any reaction to the blow, states he was finally beginning to understand what martial arts were. When questioned by Suiryu what his conclusions were, Saitama says that they basically consisted of "moving around in a way that's kinda cool".

Enraged, Suiryu rushes in Saitama's direction, who is clumsily spinning around trying to imitate Suiryu's spinning technique. This results in an accidental hip strike from Saitama, which adding to Suiryu's tremendous momentum, sends Suiryu flying away from the ring into the crowd, thus ending the battle.

Aftermath
Suiryu is left in shock at Saitama's strength and hopes not to run into him in the future. Saitama is chased away by the security staff while Suiryu is awarded with the prize money.