This year's Comic Relief single sold over 113,000 copies this week, becoming the fastest-selling single of 2013 so far.
The Blondie and Undertones cover is their third UK single to date, and their sixth Top 10 hit in less than 18 months.
Macklemore and Ryan Lewis are a non-mover at two with former number one 'Thrift Shop', while Baauer stays at three with 'Harlem Shake'.
Justin Timberlake's Brit Awards performance sees him climb a big 24 places to four with 'Mirrors'. His previous top five hit 'Suit & Tie' also rises two to 14.
Last week's number one 'I Could Be the One' from Avicii and Nicky Romero drops four to complete the top five.
Taylor Swift climbs six places to six with 'I Knew You'd Be Trouble'. Bruno Mars is a non-mover at seven with 'When I Was Your Man', while Rihanna drops four to eight with 'Stay'.
Ben Howard's Brit Awards performance and success helped him climb a massive 181 places to nine with 'Only Love'. Emeli Sandé drops one to ten with 'Clown'.
Mumford & Sons re-enter the Top 40 at 12 with 'I Will Wait' after performing it at the Brit Awards. Ellie Goulding climbs eight to 13 with 'Explosions'.
Olly Murs enters at 23 with his latest single 'Army of Two'. Pink climbs a further eight spots to 16 with 'Just Give Me a Reason'.
Adele climbs back up 14 places to 25 with 'Skyfall' after winning the 'Best Single' prize at the Brit Awards and the release of Skyfall on DVD.
The Script enter at 36 with 'If You Could See Me Now', while Tyler James is new at 38 with 'Worry About You'. Robbie Williams re-enters at 39 with 'Candy' thanks to another Brits performance.
Watch the video for One Direction's number one single below:
Source: Official Charts Company
> This week's albums chart