Katy Perry posts back-to-back No. 1s on the Billboard Hot 100, as “Teenage Dream” is set to top the chart when it’s released in full tomorrow morning (Sept. 9).

The last female artist to post successive No. 1 singles on the chart was Lady Gaga, who took her first two entries, “Just Dance” and “Poker Face,” to the summit in the first half of 2009.

Perry spent six weeks at No. 1 with her last radio single “California Gurls” earlier this summer, accumulating enough time in the upper reaches of the chart to lead the Summer Songs tally for most of the season. The final ranking of Top Summer Songs will also be announced tomorrow. On this week’s Hot 100, “California Gurls” dips 7-10.

“Teenage Dream” makes its surge to No. 1 thanks in part to a copping a second straight Airplay Gainer award, topping 100 million listener impressions for the first time with a 19% audience gain (7-5 on Radio Songs), according to Nielsen BDS. The track holds at No. 1 for a second week on Digital Songs with 221,000 (down 15%), according to Nielsen SoundScan.

Perry supplants Eminem, who was also enjoying a back-to-back No. 1 run on the Hot 100. “Love the Way You Lie,” featuring Rihanna, led for the past seven weeks (1-2), while his last single “Not Afraid” topped the chart for a week in May.

Source: Billboard