Kendrick Lamar’s surprise Untitled Unmastered project debuts at No. 1 on the Billboard 200 chart, earning 178,000 equivalent album units in the week ending March 10, according to Nielsen Music. Of that sum, 142,000 were in pure album sales.

The set was released without advance notice on March 4 and gives Lamar his second chart-topping set in less than a year, following To Pimp a Butterfly. The latter (his first No. 1) was released on March 16, 2015, and bowed atop the list with 363,000 equivalent album units in its first week, of which 324,000 were in pure album sales.

The Billboard 200 chart ranks the most popular albums of the week in the U.S. based on multi-metric consumption, which includes traditional album sales, track equivalent albums (TEA) and streaming equivalent albums (SEA). The new March 26-dated chart (where Lamar is No. 1) will be posted in full to Billboard’s websites on Tuesday, March 15.

Lamar is the third act since January 2015 to notch two No. 1s in less than 12 months time, following Drake and Future.

Drake led the list twice in 2015 with If You’re Reading This It’s Too Late and his Future collaboration What a Time To Be Alive. Future took it a step further and notched three No. 1s in less than seven months (between August 2015 and February 2016) with DS2, What a Time To Be Alive and Evol.

Lamar tweeted that Untitled Unmastered consists of “demos from To Pimp a Butterfly. In raw form.” Like the album’s title, its tracks are named unconventionally: “untitled 01 | 08.19.2014.,” “untitled 02 | 06.23.2014.” and so on.

Untitled Unmastered was released to digital retailers and streaming services on March 4 through Top Dawg/Aftermath/Interscope Records. (Streaming equivalent units comprise 16 percent of the new album’s total first-week units.)

A physical CD release of Untitled’s explicit edition followed on March 11, while an edited version is due out March 18.

Elsewhere in the top 10, Adele’s 25 holds steady at No. 2 (61,000 units; down 18 percent) and Rihanna’s Anti is also a non-mover at No. 3 (58,000 units; down 18 percent).

2 Chainz notches his third straight top five album, as ColleGrove bows at No. 4 with 53,000 units (and 34,000 in pure album sales). It follows his No. 3-peaking B.O.A.T.S. II #MeTime (No. 3 debut and peak in 2013) and his chart-topping Based on a T.R.U. Story (2012).

ColleGrove (which features Lil Wayne on eight of its 12 tracks), like Lamar’s new set, is currently only available via digital retail and streaming services. A commercial release for its physical CD is slated for March 25, when both its explicit and edited editions are due.

At No. 5 on the new Billboard 200, Justin Bieber’s Purpose is stationary with 53,000 units (down 5 percent) in its 17th chart week. The album has remained in the top five every week since its release.

Joey + Rory’s Hymns climbs 10-6 with 45,000 units (up 35 percent) and 44,000 copies sold (up 36 percent), following the death of the duo’s Joey Feek on March 4 of cancer.

The album returns to No. 1 on the Top Country Albums chart (stepping 2-1) and notches its fourth straight week at No. 1 on the Top Christian Albums chart.

As for the rest of the top 10 on the Billboard 200, Chris Stapleton’s Traveller holds at No. 7 (39,000 units; down 9 percent) and Twenty One Pilots’ Blurryface is also stationary at No. 8 (34,000 units; down 5 percent). The Weeknd’s Beauty Behind the Madness rises 12-9 with just over 30,000 units (though it’s down 8 percent), and Kevin Gates’ Islah ascends 13-10 with 30,000 units (down less than 1 percent).