The 'Rolling In The Deep' singer held strong at number one after posting impressive second week sales of over 135,000 copies, while her 2008 debut 19 is also a non-mover at four.
Second place this week goes to Chase & Status and No More Idols, while a posthumous Eva Cassidy collection, released under the title Simply Eva, lands at six.
Meanwhile, Rumer's Seasons Of My Soul continues to zip up and down the chart, this week climbing back into the top ten at nine after falling to 12 last Sunday.
Elsewhere, Plan B's The Defamation Of Strickland Banks, which arrived at number one back in April 2010, begins to plunge down the chart after falling six places to 16. By contrast, Take That's Progress and Katy Perry's Teenage Dream both enjoy minor boosts up the rankings, bumping up two spots to 12 and 17 respectively.
In the outer limits of the top 20, new releases from Skepta and Roberta Flack make themselves at home, with the former's Doin' It Again settling in at 19 and Flack landing right behind with Love Songs.
The top ten in full:
1. (1) Adele: '21'
2. (-) Chase & Status: 'No More Idols'
3. (2) Bruno Mars: 'Doo Wops & Hooligans'
4. (4) Adele: '19'
5. (3) Rihanna: 'Loud'
6. (-) Eva Cassidy: 'Simply Eva'
7. (6) Ellie Goulding: 'Lights'
9. (12) Rumer: 'Seasons Of My Soul'
10. (5) Cee Lo Green: 'The Lady Killer'
Source: Official Charts Company
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