Taylor Swift, who ended the American rapper's month-long stint at the top last week, falls to two with 'Love Story'.
Elsewhere, Ciara and Justin Timberlake's 'Love Sex Magic' is the highest new entry, debuting at six. Meanwhile, New Zealand indie rock act Evermore climb to eighth with 'Hey Boys And Girls'.
On the album chart, Kings of Leon's Only By The Night spends another week at number one, holding off competition from Australian Idol winner Wes Carr.
The top ten singles in full (click where possible for our reviews):
1. (2) Flo Rida ft. Ke$ha - 'Right Round'
2. (1) Taylor Swift - 'Love Story'
3. (3) Beyoncé - 'Halo'
4. (5) The All-American Rejects - 'Gives You Hell'
5. (4) T.I. ft. Justin Timberlake: 'Dead And Gone'
6. (-) Ciara ft. Justin Timberlake - 'Love Sex Magic'
7. (9) The Fray - 'You Found Me'
8. (12) Evermore - 'Hey Boys And Girls (Truth of the world Pt.2)'
9. (7) Lily Allen -'The Fear'
10. (10) A.R. Rahman featuring The Pussycat Dolls - 'Jai Ho!'