U.K. vocal group the Wanted becomes the first boy band to rule Mainstream Top 40 with a debut single since Hanson spent eight weeks at No. 1 with "MMMBop" in 1997, as "Glad You Came" (Island Def Jam) rises 2-1.
The Wanted is the first boy band to lead the list since O-Town topped the tally for four weeks in 2001 with "All or Nothing."
Perhaps surprisingly, the two signature boy bands of the Nielsen era - Backstreet Boys and 'N Sync - each failed to reach the Mainstream Top 40 summit so quickly. Backstreet Boys needed seven chart visits to reign until "I Want It That Way" rose to No. 1 in 1999. "Show Me the Meaning of Being Lonely" returned the group to the top spot in February 2000.
'N Sync also didn't reach No. 1 until its seventh chart entry, "Bye Bye Bye," spent 10 frames in charge in 2000. "It's Gonna Be Me" followed with a five-week command.
Island Def Jam president/COO Steve Bartels  believes that, ultimately, "Glad," which has so far climbed to No. 3 on the Billboard Hot 100 and has sold 1.5 million downloads, according to Nielsen SoundScan, stands on its own merits.
"Judging from the explosive reception to (the song) at radio and online, the appeal of that sound is as solid as ever, no matter how you describe it, a boy band or simply a male pop vocal group, which is what the Wanted is," Bartels says.
"We have seen proof of this over the past several weeks with sales and when the 'Glee' cast covered the song (on its Feb. 21 episode). No matter what name you give the Wanted's style, people of all ages have connected with the group.
"That connection is priceless," Bartels says.
"We never thought we'd get the opportunity to even come over here and have a chance to let people hear our music," the Wanted - Max George, Siva Kaneswaran, Jay McGuiness, Tom Parker and Nathan Syke - recently told Billboard of its budding stateside success.
"Thankfully, they like it."