After several days of concern over whether Floyd Mayweather Jr. would sign the contract for an agreed-upon showdown with welterweight titleholder Shane Mosley, he put pen to paper on Wednesday and signed the contract, Mosley attorney Judd Burstein told ESPN.com.
That was the last hurdle to finalizing the super fight. Mosley signed on Friday.
Mosley will defend his title against Mayweather on May 1 (HBO PPV) at the MGM Grand in Las Vegas.
"He signed. It's going to be a great fight," Burstein said.
Burstein said he received the news on Wednesday afternoon from Golden Boy Promotions CEO Richard Schaefer, who had been told by Al Haymon, a Mayweather adviser. Burstein said he then spoke to Haymon.
"Al Haymon's word is gold to me. He told me personally," Burstein said. "We spoke and he said Floyd signed. It was a short but happy conversation. Shane is excited. We all know it's going to be a great fight."
Later Wednesday, the fighters issued statements.
"This one is definitely for the fans as I wasn't going to waste anyone's time with a meaningless tune-up bout and asked to fight Shane immediately," Mayweather said. "I have said ever since I came back to the sport that I only wanted to fight the best. I think Shane is one of the best, but come May 1, he still won't be great enough to beat me."
Said Mosley, "I have always wanted to fight Floyd and now it is finally coming true. I am already in great shape and ready to show everyone on May 1 that I am stronger, faster and better than he is. I will have no problem beating him."
Schaefer and Burstein had voiced concern on Tuesday when Mayweather had still not yet signed several days after Mosley had signed and the Mayweather side said it had agreed to the terms.
Getting the contract signed this week was pivotal because Schaefer planned for the fighters to go to Miami this weekend to kick off the promotion with a variety of media appearances at the Super Bowl.
That was the blueprint Schaefer followed before the Mayweather-Oscar De La Hoya fight in May 2007. They also went to the Super Bowl to kick off the promotion and the result was the highest grossing pay-per-view in history.
Mayweather (40-0, 25 KOs), a five-division champion, and Mosley (46-5, 39 KOs), a three-division champion, have seemingly been on a collision course since the late 1990s, when Mosley was lightweight champion and Mayweather was junior lightweight champion.
Now, the fight is on, having come together under unusual circumstances.
Mayweather had been close to a deal with Manny Pacquiao for a March 13 fight, but that fell apart in early January after the camps had worked out everything except for the drug testing protocol, which they could not agree upon.
Not long after that, Mosley's Jan. 30 unification bout with Andre Berto was canceled when Berto, a Haitian-American, withdrew from the fight after eight members of his family were killed in the earthquake that ravaged the Caribbean nation.
At Mayweather's insistence, both fighters have agreed to undergo Olympic-style drug testing for the fight.
"Floyd has been trying to make this fight for the last 10 years, so he is extremely excited about the opportunity to face Shane," said Leonard Ellerbe, a Mayweather adviser. "He can't wait to extend his undefeated record and perform at the highest level. More importantly, he is also happy to set the precedent for random blood testing in order to ensure fair and safe contests for all fighters."
Mosley was linked to the BALCO scandal, admitting during grand jury testimony, which was later released, that he had used designer steroids "the clear" and "the cream" and injected himself with EPO, a blood oxygen enhancer, during the lead-up to his 2003 rematch with Oscar De La Hoya. Mosley said he took the steroids unknowingly.
"When two champions of this caliber meet in the ring, you can expect nothing but excellence and that is what we are going to see on May 1," Schaefer said. "Shane Mosley is one of the greatest fighters of this era and I commend him for not only agreeing to the fight against Mayweather, but also agreeing to participate in a testing process that can only help the integrity of the sport."
Mayweather came out of an 18-month retirement in September to easily outpoint lightweight champ Juan Manuel Marquez.
Mosley hasn't fought in 13 months, when he upset Antonio Margarito, knocking him out in the ninth round to win a welterweight title for the second time.
Dan Rafael is ESPN.com's boxing writer.