The Tottenham-born rapper, aka Jermaine Scott, knocked album chart champions Nero and their 'Promises' record from pole position with his third release of 2011.
"To be honest, if someone told me this was going to happen this time last year, I probably would have laughed," he told the Official Charts Company. "I would have thought they were winding me up."
'Don't Go' leads an all-new top three, also populated by Scottish singer Emeli Sandé's debut single 'Heaven' and Maroon 5's team-up with Christina Aguilera 'Moves Like Jagger'.
David Guetta, Taio Cruz and Ludacris, meanwhile, are forced down three to seven with 'Little Bad Girl', as former chart-toppers JLS and The Wanted drop to the depths of the best-sellers with 'She Makes Me Wanna' and 'Glad You Came', down seven and four respectively.
Former X Factor star Cher Lloyd manages just two weeks in the top ten with 'Swagger Jagger', which is down eight to this Sunday's 11, while DJ Fresh and Nicki Minaj tumble four spots each with their tracks 'Louder' and 'Super Bass' at 13 and 15.
The new entries continue at 16 with London dubstep group Modestep and their latest release 'Sunlight', one spot ahead of 'Marry Me' by Bruno Mars, up a massive ten numbers from last Sunday's 28.
Pitbull and Katy Perry snatch the final two positions in the Top 20 with 'Give Me Everything' and 'Last Friday Night (T.G.I.F.)', which are down seven and five respectively, while the latest records from Jessie J and Nicole Scherzinger, entitled 'Who's Laughing Now' and 'Wet', jump 16 each to 21 and 22.
The Top 10 in full:
1. (-) Wretch 32 ft. Josh Kumra: 'Don't Go'
2. (-) Emeli Sandé: 'Heaven'
3. (-) Maroon 5 ft. Christina Aguilera: 'Moves Like Jagger'
4. (5) Christina Perri: 'Jar Of Hearts'
5. (1) Nero: 'Promises'
6. (7) Ed Sheeran: 'The A Team'
7. (4) David Guetta ft. Taio Cruz & Ludacris: 'Little Bad Girl'
8. (8) Rizzle Kicks: 'Down With The Trumpets'
9. (2) JLS ft. Dev: 'She Makes Me Wanna'
10. (6) The Wanted: 'Glad You Came'
Source: Official Charts Company
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