"Sugar" Shane Mosley is 41 and 0-3-1 in his last four fights -- with each loss a one-sided decision -- but the former champion is ending his retirement for a world title shot.

Mosley will challenge welterweight titlist Paulie Malignaggi on April 27 at the Barclays Center in Brooklyn, N.Y., Malignaggi's hometown, in a Showtime-televised main event.

Mosley told ESPN.com on Monday that the deal has been agreed to and that "on my end, it's a go."

Golden Boy Promotions chief executive Richard Schaefer also said the deal is agreed to and that the paperwork is being finalized.

"Shane came to see me in early December and said he wanted to come back for an opportunity to win a world title again, that he feels ready, that he feels he can beat Malignaggi and see if we could give him the opportunity," Schaefer told ESPN.com. "I looked in his eyes and told him he cannot make a lot of money and that a lot of people question whether he should fight. But I told him I will do what I can to give him the opportunity and that it would be up to him to prove that he has what it takes to be world champion again.

"I discussed the fight with the networks and Paulie and I felt Shane deserved the opportunity to fight for a world title again. He has accomplished so much and thrilled fight fans in so many fights, so I am happy to give him this opportunity."

The fight will mark something of a family reunion for Mosley, who will once again be trained by his father, Jack Mosley. He trained his son for most of his career. In 1998, they won the Boxing Writers Association of America awards for trainer and fighter of the year, respectively. But although they remained close personally, they have had multiple professional breakups. Jack Mosley has not been in Shane's corner since 2008. He will take over for Naazim Richardson, whom Mosley said he still has a good relationship with.

"I'm excited to have my father back with me as my coach," Mosley said. "To be able to go into a fight and (try to) win a world title again with my father in the corner, that is like a storybook. To go into a fight like this and have family in the corner and win another belt, it's going to be a great feeling."

Mosley (46-8-1, 39 KOs) has not fought since May 5, when junior middleweight titlist Saul "Canelo" Alvarez, 21 at the time, easily outpointed him in a thoroughly one-sided fight in which Mosley showed little. After the fight, Mosley half-seriously/half jokingly said, "When the kids start to beat you up, you might have to start promoting."

A month later, Mosley formally announced his retirement after a 19-year professional career in which he won five world titles in three weight classes -- lightweight, welterweight and junior middleweight -- had a career-defining welterweight championship victory against Oscar De La Hoya in 2000 and was, for a time in the early 2000s, widely considered the No. 1 fighter in the world. He also was involved in the BALCO steroids scandal, telling a grand jury that he used the designer steroids "the clear" and "the cream" -- he says unknowingly -- during training for his 2003 rematch victory against De La Hoya for the junior middleweight championship.

But since Mosley's upset ninth-round knockout of Antonio Margarito (on the night Margarito was caught trying to enter the ring with loaded hand wraps) to win the welterweight title for the second time in January 2009, Mosley is winless. He lost lopsided decisions to Floyd Mayweather Jr., Manny Pacquiao and Alvarez and struggled to a draw with Sergio Mora.

During his retirement, Mosley has spent a lot of time training his 22-year-old son, Shane Mosley Jr., who is an amateur. Mosley said he also worked out with others and felt good enough that he wanted to give boxing another go.