The song, released on Interscope Records, passes Alessia Cara's 26-week journey to No. 1 on Pop Songs with "Here," which reached the summit in February 2016.
Blanco earns his first Pop Songs No. 1 as a credited artist (in his first such appearance), although he adds his whopping 16th as both a co-writer and co-producer. He first led as a writer and producer via Britney Spears' "Circus" in 2008 and has also reigned thanks to songs recorded by 3OH!3, Kesha, Katy Perry, Taio Cruz, Gym Class Heroes, Maroon 5, Selena Gomez, Justin Bieber and Major Lazer.
Halsey claims her fourth Pop Songs No. 1, after The Chainsmokers' "Closer," on which she's featured (11 weeks, 2016); "Him & I," with G-Eazy (two weeks, 2018); and her own "Without Me," which "Eastside" displaces after four weeks at the summit.
Halsey is the first artist to succeed herself directly atop Pop Songs with a new No. 1 since Iggy Azalea in July 2014, when Ariana Grande's "Problem," featuring Azalea, took over for Azalea's "Fancy," featuring Charli XCX.
Halsey is the fourth artist to swap out No. 1s on Pop Songs and the third as a lead on both songs; OutKast's "The Way You Move," featuring Sleepy Brown, ended the reign of the pair's "Hey Ya!" in 2004, while Mariah Carey's "One Sweet Day," with Boyz II Men, replaced her own "Fantasy" at No. 1 in 1995.
Honorable mention to Maroon 5 frontman Adam Levine: "Stereo Hearts," by Gym Class Heroes featuring Levine, supplanted Maroon 5's "Moves Like Jagger," featuring Christina Aguilera, in 2011. (Both songs were co-written and co-produced by Blanco.)
Meanwhile, Khalid collects his second Pop Songs leader, after "Love Lies," with Normani, ruled for two weeks in September and subsequently tied Dua Lipa's "New Rules" for the longest run on the chart (45 weeks) in the list's history. He concurrently earns his fourth Pop Songs top 10, as "Better" bumps 11-9.
All charts will update tomorrow (Feb. 26) on Billboard.com.