Sales of 21 picked up last week, outperforming the market by increasing 9.70% to 80,922.
Four songs from the album are now in the Top 75 - first single Rolling In The Deep dips 26-27 (13,379 sales), second single Someone Like You improves 12-11 (25,920 sales), third single Set Fire To The Rain debuts at number 44 (6,286 sales), after spending 14 weeks in the 76-200 region of the chart, and album track Turning Tables debuts at number 62 (4,320 sales), primarily on sales triggered as a result of Glee Cast/Gwyneth Paltrow's cover in the most recently screened edition of Glee, which also generates enough sales for their version to debut at number 75 (3,513 sales).
Bruno Mars' Doo-Wops & Hooligans, Chase & Status' No More Idols, Mumford & Sons' Sigh No More, Jessie J's Who You Are, Elbow's Build A Rocket Boys! and Katy B's Katy On A Mission have all peaked at number two behind 21, and they are joined this week by Fleet Foxes' second album, Helplessness Blues, which debuts in runners-up slot on sales of 46,681 copies.
It instantly beats the debut position, peak and highest weekly sale achieved by their self-titled debut, which entered at number 11 in June 2008 on sales of 13,826 copies, and peaked at number three in February 2009 (34 weeks later) when it also achieved its highest weekly sale of 21,952 copies after being reissued as a two disc set.
While first single On The Floor falls 3-5 and extends its stay in the top five to six weeks - twice as long as any of her previous singles - Jennifer Lopez's new album Love debuts at number six (15,931 sales), becoming her fourth Top 10 album, and easily eclipsing the number 24 debut/peak of her last album, 2007's Brave.
The Beastie Boys' fifth album Hello Nasty provided the second of only 15 number one rap albums when it topped the chart in 1998.
Their eighth album, Hot Sauce Committee Part Two, debuts at number nine (13,200 sales) more than 24 years after their debut, Licensed To Ill, peaked at number seven, and four years after last album, The Mix-Up, reached number 79.
Two other albums sold enough copies last week to secure Top 40 debuts: Cambridge pop/punk/boy band/trio Twenty Twenty's debut album Small Talk debuts at number 26 (exactly 4,500 sales), even though its first offcut, Love To Life, reached only number 60 on the singles chart; and Glasgow band Twin Atlantic's second album, Free, debuts at number 37 (3,365 sales), far surpassing their 2009 debut Vivarium, which reached only number 148, and has sold 5,209 copies. It is number four in Scotland, where Vivarium reached number 28.
Now That's What I Call Music! 78 completes a fourth week atop the compilation chart (38,357 sales).
After plunging to their lowest level in the current century a fortnight ago, album sales staged a very modest recovery last week, climbing 0.95% to 1,562,663.
That's 9.37% below same week 2010 sales of 1,724,309, and their second lowest level in 592 weeks in the 21st century, beating only the previous week's tally.
The only bright spot is digital, with album downloads of 414,185 representing a 26.51% share of the market - a new record.
Meanwhile, Bruno Mars is still waiting for his third number one hit from debut album Doo-Wops & Hooligans, as The Lazy Song is becalmed at number two, despite increasing sales 22.85% week-on-week to 61,393.
It is not quite enough to dethrone LMFAO, whose Party Rock Anthem sold a further 64,508 copies to claim pole position for the fourth week in a row.
David Guetta racks up his 18th hit and 10th Top 10 entry - both records for a Frenchman - debuting at number three with Where Them Girls At (54,848 sales). The first single from Guetta's upcoming fourth album, it also features Flo-Rida and Nicki Minaj. Guetta is still in the Top 10 with Sweat - his collaboration with Snoop Dogg, which dips 5-6, selling a further 37,478 copies.
Singles sales are up 0.26% week-on-week at 3,019,753, 15.70% above same week 2010 sales of 2,609,959.