Danny Jacobs needed the big challenge, wanted to fight a guy who even some of boxing's best wouldn't.

Jacobs won the IBF middleweight title, pulling out a thrilling split decision over Sergiy Derevyanchenko.

Jacobs scored a first-round knockdown and that helped him build just enough of a lead to hold on in a tight finish in which both fighters were swinging wildly across the late rounds.

He won 115-112 on Tom Schreck and Steve Weisfeld's cards, while judge Julie Lederman scored it 114-113 for Derevyanchenko.

"Hats off to Sergiy. I knew he was a true competitor," Jacobs said. "I knew he was going to be hard so I had to dig deep."

Jacobs (35-2, 29 KOs) took the belt that was vacated when Gennady Golovkin chose not to fight Derevyanchenko, his mandatory challenger, this spring while awaiting his rematch with Canelo Alvarez.

Alvarez won that bout and is moving up to super middleweight for his next one. He's expected to return to 160 pounds afterward and Jacobs, who narrowly lost to Golovkin last year, wants to be the opponent.

"The fans want it," Jacobs said. "Now I have the strap, let's do it. I'd rematch Triple G but he's not a champion. I want the champs."

Jacobs and Derevyanchenko share a manager, have worked with the same trainers and sparred against each other in Brooklyn. Jacobs said it would be bittersweet working against people he’d known for so long.

Their familiarity may have caused a cautious beginning, with neither throwing a punch in the opening half-minute as they sized up each other. Jacobs got aggressive later in the round and scored a knockdown when Derevyanchenko’s gloves touched the canvas after Jacobs’ overhand right along the ropes.

But Derevyanchenko rallied nicely and caught Jacobs with a good left hook in the second, fought well again in the third and both connected well in the fourth. They both landed and missed with wild punches in a back-and-forth sixth, each shaking his head during the round to show he had taken a good punch.

Derevyanchenko kept coming and started catching Jacobs again in the later rounds.

“It was a great fight, he’s a tremendous competitor and I’d like to fight him again soon,” Derevyanchenko said.