The release, which rocketed to the top of the U.K. charts on Sunday (22Mar15), is also the star's first number one in the U.S.

To Pimp a Butterfly was scheduled for release on 27 March (15), but it was pushed forward following an online leak earlier this month (Mar15).

The album still managed to shift 324,000 copies in its first week - 100,000 more than Lamar's critically-acclaimed 2012 release good kid, m.A.A.d city in its opening seven days.

The Empire soundtrack slips to two on the new chart, while indie rockers Modest Mouse debut at number three with Strangers To Ourselves.

The Fifty Shades of Grey soundtrack and Taylor Swift's 1989 round out the new top five.

Meanwhile, in the Billboard singles chart, Mark Ronson and Bruno Mars have topped the Hot 100 for a 12th week.

Uptown Funk becomes just the 15th number one in five decades to score at least 12 weeks at number one.

Maroon 5's Sugar stays put at two and Ed Sheeran's Thinking Out Loud rounds out the top three.