The duo extend their lead at the top after a total of 21 weeks on the tally, fending off Foster The People's 'Pumped Up Kicks', which leaps from 12 to 2, while Coldplay jump from six to complete the top three.
Meanwhile, Guy Sebastian's 'Don't Worry Be Happy' slips from five to seven, and Lloyd, Andre 3000 and Lil Wayne's 'Dedication To My Ex (Miss That)' climbs 11 to ten.
Further down the chart, Timomatic advance from 17 to 12 with 'Set It Off', Gotye's 'Somebody That I Used To Know' lifts 21 to 15, and Simple Plan and K'naan's 'Summer Paradise' vaults from 40 to 22.
Flo Rida and Sia's 'Wild Ones' shifts from 29 to 24, Laurent Wery's 'Hey Hey Hey' ascends from 48 to 32, and LMFAO's 'Sorry For Party Rocking' climbs 49 to 38.
The Top 10 singles in full (click where possible for our reviews):
1. (1) LMFAO: 'Sexy And I Know It'
2. (12) Foster The People: 'Pumped Up Kicks'
3. (6) Coldplay: 'Paradise'
4. (3) Ed Sheeran: 'The A Team'
5. (2) Reece Mastin: 'Good Night'
6. (3) Taio Cruz: 'Hangover'
7. (5) Guy Sebastian: 'Don't Worry Be Happy'
8. (7) One Direction: 'What Makes You Beautiful'
9. (8) Flo Rida: 'Good Feeling'
10. (11) Lloyd ft. Andre 3000 and Lil Wayne: 'Dedication To My Ex (Miss That)'
Watch the 'Sexy And I Know It' music video below: