Jessie J remains at the top of charts, making it two weeks at number one with her hit Price Tag featuring B.O.B.
The 22-year-old Brit winner held out after a tight battle with Champion - the new single from precocious rap talent Chipmunk featuring R&B star Chris Brown, the Official Charts Company confirmed.
Champion, the new entry at number two, was leading the way in Wednesday's Official Chart Update, but Price Tag regained the lead in the last two days.
Both singles recorded strong sales of more than 90,000 each; the winning margin was less than 5%.
Champion is the eighth Top 40 hit and third Top 10 for the North Londoner (aka Jahmaal Noel Fyffe) who is still just 20 years old and whose career highlights already include number one single Oopsy Daisy (2009) and a number two album.
Global superstar Lady Gaga's new single Born This Way was straight in at number three selling 60,000 copies-plus in just 34 hours. Born This Way was released worldwide at 2pm on Friday having been moved forward from Sunday's original release date.
In the Official Albums Chart, Adele held on to the number one slot for a third week with her second album 21 continuing to post strong weekly sales of more than 130,000 - more than the rest of the Top 5 combined.
The chart saw two new entries. Computers And Blues entered at number eight, giving The Streets a fifth Top 10 album and the last if founder Mike Skinner holds good on his decision to end the band.
James Blake, who was runner-up to Jessie J in the BBC's Sound of 2011 poll, landed straight in at number nine with his debut album, the self-titled James Blake.