After a nail-biting seven-week wait at No. 2, LMFAO's "Sexy and I Know It" at last struts to the top of the Billboard Hot 100 as the chart's top Digital Gainer during the robust sales week leading up to Christmas Day.

"Sexy" assumes control of the Hot 100 by logging a fourth week at No. 1 on the Digital Songs chart, selling 395,000 downloads (up 159%), according to Nielsen SoundScan, over the Dec. 19-25 sales tracking week. The song stays at No. 3 on Radio Songs with 103 million in all-format audience, according to Nielsen BDS.

As the duo's prior single, "Party Rock Anthem," featuring Lauren Bennett and GoonRock, led the Hot 100 for six weeks (on its way to becoming Billboard's biggest Song of the Summer), LMFAO is the first duo to notch back-to-back No. 1s on the chart since OutKast ruled for nine weeks with "Hey Ya!" beginning Dec. 13, 2003, and replaced itself in the penthouse with "The Way You Move," featuring Sleepy Brown, the week of Feb. 14, 2004. (LMFAO and OutKast are the only twosomes to lead the Hot 100 with successive singles since Roxette in 1990-91).

"Sexy and I Know It" brings "sexy" back to the Hot 100's pinnacle for a fourth visit. The three previous No. 1s with the word "sexy" in their titles? Rod Stewart's "Da Ya Think I'm Sexy?" (four weeks at No. 1, 1979); Right Said Fred's "I'm Too Sexy" (three, 1992); and, Justin Timberlake's "SexyBack" (seven, 2006).

LMFAO's "Anthem," meanwhile, returns to the Hot 100's top 10 (15-9), spurred by a 170% increase to 214,000 downloads sold. The song racks a 27th week in the top tier, a sum that only three titles have bested: LeAnn Rimes' "How Do I Live" (32 weeks, 1997-98); Santana's "Smooth," featuring Rob Thomas (30, 1999-2000); and, Jewel's "Foolish Games/You Were Meant for Me" (28, 1997-98). "Anthem" passes Savage Garden's 26-week top 10 stay with "Truly Madly Deeply" in 1997-98.

The coronation of "Sexy" dethrones Rihanna's "We Found Love," featuring Calvin Harris, after eight weeks at No. 1 -- Rihanna's longest Hot 100 command. "Love," now at No. 2 on the Hot 100, spends a sixth week in charge of Radio Songs (148 million), while slipping 2-3 on Digital Songs (276,000, up 86%).

Katy Perry's "The One That Got Away" rises 5-3 on the Hot 100 and is just two notches from making parent album "Teenage Dream" the first set to generate six No. 1s in the survey's history. The track bounds 6-2 on Digital Songs (297,000, up 157%) and lifts 5-4 on Radio Songs (99 million, down 1%). In its first week of availability, the B.o.B-assisted remix of "One" accounted for 26% (76,000) of the title's overall digital sales in the chart's tracking period.

Bruno Mars' "It Will Rain" dips 3-4 on the Hot 100, Jay-Z and Kanye West's "Ni**as in Paris" ascends 6-5 and Flo Rida's "Good Feeling" drops 4-6.

Adele -- Billboard's top artist of 2011 -- scores her third Hot 100 top 10 from "21" -- Billboard's top album of the year -- as "Set Fire to the Rain" blasts 13-7 as the chart's top Airplay Gainer. "Fire" burns 20-17 on Radio Songs (50 million, up 16%) and holds at No. 7 on Digital Songs (217,000, up 118%). The song follows Adele's seven-week Hot 100 leader "Rolling in the Deep" -- Billboard's No. 1 song of 2011 -- and five-week topper "Someone Like You," which ranks directly below "Fire" (7-8).

As LMFAO and Adele each hold two spots in the Hot 100's top 10, they are the first acts to so double up since Bruno Mars ranked at Nos. 1 ("Grenade") and 9 ("Just the Way You Are") and Rihanna held the Nos. 3 ("What's My Name") and 10 ("Only Girl (In the World)") spots the week of Jan. 22, 2011.

Below "Party Rock Anthem" at No. 9, Big Sean rounds out the Hot 100's top 10, as "Dance (A$$)," featuring Nicki Minaj, shakes 12-10. The song marks Big Sean's first Hot 100 top 10 and Minaj's fourth.