Danny Jacobs, once the top middleweight prospect in the United States, came back to the sport after beating cancer with a first round knockout of Josh Luteran tonight at the Barclays Center in Brooklyn.

Jacobs (23-1, 20 KO) hadn't fought since March 2011, and hadn't really been heard from by most boxing fans since he lost to Dmitry Pirog in July 2010. Tonight's win came against a limited opponent in Luteran (13-2, 9 KO), but that was more than "acceptable," given the incredible circumstances. This is a young man looking not just to "return," but to basically rebuild a career against all odds -- real odds, not boxing odds.

It was a vicious uppercut that put Luteran on the canvas, where he slammed his head on the mat and was immediately out. It was a nasty KO, but Luteran was up and responsive shortly after. Jacobs did his job tonight, and while there's certainly more to learn about where Jacobs is really at, this was a great moment for him, and really for anyone watching.

"This moment is super sweet, and I'm glad I gave these Brooklyn fans a good show," Jacobs said after the fight to Showtime's Jim Gray.

Our live coverage will continue, with the main Showtime card starting at 8 pm ET.