🌍 Scene: A barren wasteland, shattered moonlight overhead

The planet’s surface quakes from the presence of two impossible forces.

On one side stands Goku in his Ultra Instinct form — body glowing with divine silver aura, expression focused, calm.

On the other stands Saitama, in a loose tracksuit, hand in his pocket, cape fluttering. His face is blank — half bored, half curious.

Goku (floating, smiling):
“I’ve fought gods, destroyers, and even time travelers… But your energy… it’s different. I can’t sense it at all.”

Saitama (yawns):
“Oh, I don’t really do ‘energy.’ Just punches. You done talking?”

💨 Round One: The Approach

Goku vanishes — reappearing behind Saitama.

Boom.

His palm strike misses by a hair.

Saitama ducks lazily, steps forward, and flicks a rock toward Goku. It breaks the sound barrier, forcing Goku to dodge with a teleport.

They exchange blows — Goku blazing around with Ultra Instinct after-images, throwing flurries faster than light.

Saitama deflects them casually. One hand. No stance.

Goku’s eyes narrow.

“He’s not even trying…”

---

🌌 Round Two: Escalation

Goku backs off, breathing calmly. Then—

“HAAAAA—!!”

He powers up to Mastered Ultra Instinct, erupting in cosmic silver light. The sky splits, nearby mountains vaporize.

Saitama (blinking):
“Whoa. That’s pretty.”

Goku dashes in — this time faster than before. His strikes hit Saitama squarely, blasting him backward through dozens of mountains.

Goku:
“Maybe you do have limits.”

Saitama walks out of the crater. Unharmed. Cape torn a little.

Saitama (slightly annoyed):
“Okay. That was actually kinda strong. My turn.”

---

💥 Round Three: The Serious Punch

The earth stops vibrating. The wind calms.

Saitama takes one step forward.

His aura changes.

He’s serious.

Goku instinctively raises his guard, sensing an overwhelming pressure. Not ki. Something else.

Saitama vanishes.

In an instant — he appears right in front of Goku and throws…

A Serious Punch.

Not at full power.

Just serious enough.

---

🌌 Impact

The punch doesn’t touch Goku.

But the shockwave behind it obliterates the sky. Clouds part planet-wide. Oceans ripple.

Goku is launched into orbit — bouncing off the atmosphere like a pebble on water — then crashing into the moon.

Saitama appears beside him before he can move.

Saitama (looking bored again):
“Hey, are we done yet? I need to buy leeks.”

---

🏁 Aftermath

Goku sits up, bruised, stunned… and smiling.

Goku:
“You win. No question. That power… it’s not from this universe.”

Saitama scratches his head.
“Cool. So… can I go?”

They shake hands.

Goku laughs, energized.

Goku:
“Maybe we’ll spar again someday. You’re the strongest I’ve ever met.”

Saitama:
“Huh. I get that a lot.”

---

✅ Winner: Saitama

✍️ Notes:

• Goku fought seriously and used Ultra Instinct.
• Saitama used a Serious Punch, not even at full strength.
• The story respects both characters’ personalities and power logic.