I'm going with another underdog here. Spivac isn't exactly a killer, but he is tough, very big and is an actual fighter. Vitor is an athlete who decided to become a fighter, that's very different. Where Vitor may be faster, Spivac will be grittier, where Vitor may hit harder, Spivac will have the better fundamentals and the ability to work through the punches to get to the takedowns. I see this fight being very similar to Vitor's last fight, but Spivac is 10x the grappler that Asplund is and should be able to work in his own takedowns. The only real concern I have here is that this is one of very few weight classes where athleticism is may actually be enough to win you a fight.

Serghei Spivac

Sergey Spivac is a heavyweight grappler who has great ground and pound with solid takedowns. He has an ok submission game and is a capable striker. He doesn't have KO power but he does have a decent jab and solid volume. His biggest issue is control where people can stand up on him. He is coming off the decision win over Ante Delija where he jabbed an old man for 15 minutes and snuck in a takedown.

Vitor Petrino

Vitor Petrino is a powerful guy with a solid left hook. He is a dangerous striker who has grappling as well. He has 17 takedowns in the UFC. His takedown defense is just ok, but he does a nice job working his way up and avoiding danger. He is evolving as a fighter technically and learning more every time he steps in the cage but he is soft mentally and has almost no heart. He is coming off the decision win over Steven Asplund where he was dropped 3 times and only won because of athleticism