The London-born rapper will win his first number one single if he manages to retain the chart position until Sunday. Last week's number one 'Give Me Everything' by Pitbull has slipped a place to two.
Nicole Scherzinger's appearance on Saturday night's Britain's Got Talent and the confirmation that she has become an official judge on The X Factor USA has had a positive effect on her new single 'Right There', which launches up 11 places to number three.
Coldplay's new release 'Every Teardrop Is A Waterfall' enters the chart at number four, while 'Mr Saxobeat' by Alexandra Stan falls two places to five.
Nicola Roberts is perched just outside the top ten with her debut solo single 'Beat Of My Drum' landing at 11 and Rihanna falls nine places to number 17 with 'California King Bed'.
Paramore's contribution to the new Transformers: Dark of the Moon soundtrack, 'Monster', is another new entry at number 23, while further down the chart Beyoncé slips five places to 34 with 'Run The World (Girls)'.
Over on the album chart, Arctic Monkeys knock Lady GaGa off the top with their fourth studio album Suck It And See and Adele's multi-million-selling album 21 remains at two.
America's Got Talent finalist Jackie Evancho is this week's second-highest new entry landing at number three with her debut record Dream With Me, while last week's number one Born This Way by Lady GaGa tumbles to four.
Other new entries in the top ten include Glee: The Music - Vol. 6 at number five, Frank Turner's England Keep My Bones at eight and Wonderland's self-titled debut album at number ten.