Katy Perry matches Rihanna's record for the most No. 1s in the almost 20-year history of Billboard's Nielsen BDS-based Mainstream Top 40 chart, as "Wide Awake" (Capitol) rises 2-1. With the coronation, Perry and Rihanna each boast nine No. 1s.

(All charts will be refreshed Thursday (Aug. 2) on Billboard.biz.)

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The shared mark is even more impressive given that while the chart launched the week of Oct. 3, 1992, Rihanna (signed to Island Def Jam) didn't first grace the list until 2005 and Perry didn't arrive until 2008.

Of the acts with the most Mainstream Top 40 No. 1s, the top seven are women. After Perry and Rihanna, Lady Gaga, P!nk and Britney Spears each have seven leaders. Beyonce and Mariah Carey follow with six apiece.

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Perry additionally holds the record for the most Mainstream Top 40 No. 1s from a single album. All six singles from her 2010 release "Teenage Dream" topped the tally: "California Gurls" (featuring Snoop Dogg), the title track, "Firework," "E.T." (featuring Kanye West), "Last Friday Night (T.G.I.F.)" and "The One That Got Away."

"Wide Awake" (and previous single "Part of Me," which reached No. 3 on Mainstream Top 40) appears on the reissue of "Teenage Dream," "The Complete Confection." All versions of the set have combined to sell 2.4 million copies, according to Nielsen SoundScan.