Jay Sean's "Down" returns to the top slot of the Billboard Hot 100 for a second time, just one week after Britney Spears' No. 1 debut bumped him to runner-up status. A predicted second-week digital sales dip (down 33%) sends Spears' "3" to No. 5 on the chart, even with radio play continuing to blossom. The suggestive track rises 49-25 on Hot 100 Airplay with a 44% audience increase.

Between Sean and Spears, Jason DeRulo's "Whatcha Say" climbs 4-2, leapfrogging Miley Cyrus' "Party In The U.S.A." which remains at No. 3. "Run This Town" by Jay-Z, Rihanna and Kanye West moves up 5-4.

Lady Gaga rebounds 7-6 with "Paparazzi" and takes Greatest Gainer/Airplay status for a fourth straight week, becoming the first female soloist to do so since Beyonce had a six-week streak with "Irreplaceable" in Nov-Dec 2006.

Owl City continues to soar, as "Fireflies" jumps 9-7 on the Hot 100 and 4-2 on Hot Digital Songs.

The Black Eyed Peas occupy the next two slots in the top 10 with "I Gotta Feeling" (6-8) and "Meet Me Halfway" (17-9). The latter track takes the Greatest Gainer/Digital award as it also climbs 17-5 on Hot Digital Songs (up 118%). Sales of "Halfway" were buoyed by the track's iTunes video premiere and its inclusion in the latest television spot for DirecTV, shown frequently during the MLB Playoffs on TBS and FOX.

Closing out the top 10 is Taylor Swift's "You Belong With Me" (8-10).

John Mayer scores his best-ever Hot 100 debut at No. 17 with "Who Says," the opening single from his upcoming album "Battle Studies," due Oct. 27. The track also starts at No. 10 on Hot Digital Songs (102,000).

Chamillionaire is back on the Hot 100 as a lead artist for the first time since he topped the list with "Ridin" in June 2006, as his new single "Good Morning" debuts at No. 40.

Also entering the chart are two more "Glee" tracks -- "Keep Holding On" and "No Air" at Nos. 56 and 65, respectively -- and the first U.S. chart appearance by South Korean pop quintet Wonder Girls, with "Nobody" at No. 76.

Another debut, Usher's "Papers" at No. 92, should take a nice jump next week, as sales from its digital release will contribute to its ranking for the first time.