Undefeated welterweight world champion Floyd Mayweather has celebrated his 37th birthday by announcing he’ll put his 45-0 record on the line on May 3 against Marcos Maidana.

The move comes after weeks of speculation as to whether Mayweather would fill his May fight date with Argentina’s Maidana or England’s Amir Khan.

The brash American even ran an internet poll in which fans voted for the Khan match-up, but World Boxing Council welterweight champion Mayweather instead will take on World Boxing Association champ Maidana in a unification bout.

“Marcos Maidana’s last performance immediately brought him to my attention,” Mayweather said of Maidana’s comprehensive defeat of the previously unbeaten Adrien Broner on December 14.

The 30-year-old Maidana dominated Broner from the opening bell and registered two knockdowns against the three-time world champion.

“He is an extremely skilled fighter who brings knockout danger to the ring,” Mayweather said. “I think this is a great fight for me and he deserves the opportunity to see if he can do what 45 others have tried to do before him – beat me.”

At 45-0 with 26 knockouts, Mayweather is approaching the 46-0 career mark of retired Welsh star Joe Calzaghe and the iconic 49-0 mark of heavyweight legend Rocky Marciano.

Mayweather beat Saul “Canelo” Alvarez last September in his most recent bout for the WBA and World Boxing Council light middleweight titles. The May 3 bout will be the third in his lucrative six-fight deal with Showtime.

“I am extremely happy to be facing Floyd Mayweather because it will give me the opportunity to show the world that I am the best welterweight in the division,” Maidana said. “I just handed a great defensive fighter his first loss and I plan to do the same to Mayweather.”