Floyd Mayweather will fight Manny Pacquiao in Las Vegas on 2 May for what promises to be the richest bout in history, it has finally been confirmed.
American Mayweather, 37, and Philippine Pacquiao, 36, are considered to be the best two fighters of their generation.
Mayweather's WBC and WBA welterweight titles and Pacquiao's WBO title will be on the line at the MGM Grand.
Mayweather is unbeaten in 47 professional fights; Pacquiao has 57 wins and five losses from 64 contests.
The fight is expected to generate as much as £162m ($250m). The most lucrative fight in history is thought to be Mayweather versus Saul Alvarez in 2013, which generated an estimated £97m.
Mayweather-Pacquiao is also expected to break the record for pay-per-view buys in the United States. The current record of 2.4m was set whenMayweather fought fellow American Oscar de la Hoya in 2007.
Mayweather wrote on his webpage: "What the world has been waiting for has arrived. Mayweather vs Pacquiao on May 2, 2015, is a done deal.
"This will be the biggest event in the history of the sport. Boxing fans and sports fans around the world will witness greatness on May 2.
Pacquiao said: "I am very happy that Floyd Mayweather and I can give the fans the fight they have wanted for so many years.
"They have waited long enough and they deserve it. It is an honour to be part of this historic event.
"I dedicate this fight to all the fans who willed this fight to happen and, as always, to bring glory to the Philippines and my fellow Filipinos around the world."
Mayweather added: "I am glad my decision to meet with Manny and discuss making this fight happen helped get the deal done.
"I promised the fans we would get this done and we did. Giving the fans what they want to see is always my main focus.
"I am the best ever and this fight will be another opportunity to showcase my skills and do what I do best, which is win.
"Manny is going to try to do what 47 before him failed to do, but he won't be successful. He will be number 48."
Pacquiao's trainer, Freddie Roach, said: "Floyd should enjoy being the A-side while he can. Because on May 2, Manny is going to put him on his backside."
Mayweather and Pacquiao met for the first time at a basketball game in Miami in January, when they exchanged telephone numbers.
Mayweather is regarded by many as the finest technician and tactician in boxing, while Pacquiao has built his career on a more aggressive style.
Pacquiao beat Chris Algieri on a unanimous points decision in his most recent fight in November, but lost twice in 2013, to Timothy Bradley and Juan Manuel Marquez.
Mayweather, whose unbeaten record stretches back to 1996, has won his past five bouts on points, most recently a rematch with Marcos Rene Maidana in September.
British welterweight Amir Khan, who wants to fights Mayweather and also held talks with Pacquiao in January, said before the Mayweather-Pacquiao bout was announced that it is "not going to be what people expect".
He told the Daily Mail on Thursday: "Four years ago it would have been a massive fight because both of them were at their peak. It might have gone past that now.
"It will be a good fight for a couple of rounds. I think it will go the distance but that Mayweather will win by unanimous decision."
Manny Pacquiao and Floyd Mayweather exchanged telephone numbers during a basketball game in January