That body shot flurry Topuria threw in round 2 was the finishing move, the man put everything in those shots, and Justin managed to keep the lights on, even if barely.
A bunch of people said that Ilia fumbled when he went to grapple after those shots when Justin was hurt, but I think that was Ilia going for a body lock or choke atempt to see if he could get some gas back, because he was dead after that, he didn't have the power to finish Gaethje.
And that is the thing, Justin is a power puncher and this is the first time Ilia got to see what being hit in the lightweights is really like. Charles also hits hard, but his fight with Topuria ended was too fast. After a couple of stiff jabs from Gaethje, Topuria looked surprised, and this is not good.
Also, I think Justin cracked Topuria's ribs with a knee on R4, that is why the call was made.
But all the credit goes to Gaethje, how he survived those bodyshots is beyond me, he should've have folded right then and there.
It was indeed a Cinderella night for the man, stuff that can only happen in combat sports.