Jack Hermansson has completed his journey from dark horse to unquestionable middleweight contender.

“The Joker” took control of his own fate on Saturday, stepping in as a late-notice replacement to fight Ronaldo Souza (26-7, 1 NC) in the middleweight main event of UFC Fort Lauderdale at BB&T Center in Sunrise, Florida, and walking out with a unanimous decision (49-46, 48-47, 48-47) victory.

There was a lot on the line for both fighters, with Souza hoping that a win over Hermansson would keep him in contention for a long-awaited shot at UFC gold, and Hermansson looking to prove that his recent surge up the rankings is no fluke. Over the course of five rounds, Hermansson emphatically made his point.

“I’m very happy, I’m just a little bit tired,” Hermansson said post-fight. “I’m very happy to be here and ready to show every single one in the world watching MMA that I am a force to be reckoned with. I am a title contender.”

Heading into the final round, the action appeared to already be leaning in Hermansson’s favor. In round one, Hermansson hurt Souza on the feet and hunted for a choke, testing the Brazilian jiu-jitsu master’s grappling defense.

Souza turned into the choke and patiently waited for his opening to slip out. Still, Hermansson stayed on him and used a body lock to keep “Jacare” neutralized against the fence.

“My coach told me that the fight [was going to be like this]. I was hoping for an early finish,” Hermansson later said, with a laugh. “It went all the five rounds, I don’t like to go to the decision, that’s why you’re not seeing me smile that much now. I like to finish fights, but I hope it was impressive anyway and I’m looking forward to finishing the next one.”

Though a finish eluded him, Hermansson’s pressure carried over into round two. Hermansson did an excellent job of mixing up his strikes, then he scored a takedown about a minute in. The rest of the period saw Hermansson put in work from mission control, just maintaining top position and scoring with enough strikes to avoid a standup.

“Jacare” stuffed a takedown to open up round three and that gave him some positive momentum as he began to find success by pressing forward. He drove punches into Hermansson’s midsection and then cracked him with an elbow and a right hand over the top.

A wounded Hermansson went into full-defense mode to recover, though he couldn’t avoid another right hand that had him stumbling to close out the round.

Hermansson may have just been saving energy in round three, because he picked up the pace again in the fourth and fifth, touching “Jacare” up from long range and staying away from Souza’s power. For every hard punch that Souza landed, Hermansson responded with three or four significant strikes of his own.

They fought tooth-and-nail to the end, with Hermansson landing a late takedown to finish in top position.

That’s four straight wins now for Hermansson (20-4), with his previous three being finishes of former World Series of Fighting two-division champion David Branch, submission specialist Gerald Meerschaert, and one-time UFC middleweight title challenger Thales Leites.

The 30-year-old Swede is now firmly in the contenders’ picture himself and his plan is to capitalize on his elevated ranking with a main event spot in Denmark later this year.

“I would like to be back, I heard there was a card in Copenhagen in October,” Hermansson said. “I would love to headline that card and give me a top name. What I ask of the UFC is to get the names that get me to that title, I’m obsessed with that title. That’s what I want in this sport. After a victory like this, I stepped in saved the show on short notice against one of the toughest guys in the world and I think I need a good reward after that.”

Souza, 39, has now alternated wins and losses in his last six fights. He defeated former champion Chris Weidman by third-round knockout at UFC 230 last November, but now finds himself having to climb back up the middleweight mountain once again.