Matt Mitrione has carved out quite a niche for himself in full-contact fighting, especially when considering the fact that he did not start competing in mixed martial arts until after the age of 30. Now a key piece of Bellator MMA’s heavyweight division, The Ultimate Fighter season 10 quarterfinalist will lock horns with Sergei Kharitonov in the Bellator 225 headliner on Saturday at Webster Bank Arena in Bridgeport, Connecticut. It serves as a rematch to their botched Feb. 15 encounter, which ended prematurely after Mitrione accidentally struck the Pride Fighting Championships veteran below the belt just 15 seconds into Round 1. The two men are jockeying for position behind current heavyweight champion Ryan Bader, and neither of them can afford a misstep. As Mitrione prepares for his second confrontation with Kharitonov, here are five things you should know about him.