Don't overreact to that Punch, it's the same Punch Luffy delivered against Krieg, Arlong, Crocodile, Enel, Doflamingo ... etc when Final Battle started
Oda have the same Scenario for Villain Fight
1. Luffy loses first encounter
2. Luffy runs to reach the Villain again
3. Luffy punches the Villain when he arrives (We are here)
4. Villain gets angry but Luffy continues to hit him more (This will happen next)
5. Villain decide to get serious & starts overwhelming Luffy with Attacks
6. The Fight temporarily stops while Luffy Recovers/Catch up again/Heal ... etc
7. Equal Clash between Luffy & Villain
8. Conclusion of Fight with Luffy victorious
However this time it's 5 v 2
So expect Supernova to have the edge next & perform very well & then Kaido gets serious & reveal his Fish Fish Fruit real ability while Big Mom also gets serious & show something new most probably (Or maybe she simply rides Kaido)
Supernova will be overwhelmed here & start kinda losing & then something will interupt the fight & make it seem as if Kaido/BM won (Some Characters will face Kaido/BM here while the Supernova recover again, most probably Yamato & Momo for starters)
Once they are ready again, they attack Kaido/BM again & we will have a cool scene where there is an Equal Clash (Similar to Luffy & Doffy/Katakuri CoC Clash mid fight)
And finally they defeat Kaido (At least, not sure about Big Mom) with a perfect team effort where they all show their best moves (I expect Luffy to use King Kong Gun fused with Red Hawk & call it Gomu Gomu No Meteor & attack Kaido from above while Kid & Law combine their Devil Fruits to create some equally big attack & attack Kaido from below while Zoro zoro's attack him face on with Asura perhaps. Overall it will be a three way attack where Luffy knocks Kaido down, Kid & Law deal even more damage & stun while Zoro cuts him)
This is my prediction