Rock band Rage Against The Machine has won the most competitive battle in years for the Christmas number one.
The band's single, Killing In The Name, sold 500,000 downloads beating X Factor winner Joe McElderry's The Climb by 50,000 copies to clinch the top spot.
Their success followed a Facebook campaign designed to prevent another X Factor number one.
One retailer said it was a "truly remarkable outcome - possibly the greatest chart upset ever".
'Sterile pop'
Speaking on the Radio 1 chart show, Zack de la Rocha from Rage said: "We are very, very ecstatic about being number one."
He added it was an "incredible organic grassroots campaign".
"It says more about the spontaneous action taken by young people throughout the UK to topple this very sterile pop monopoly," he said.
McElderry, 18, praised the campaign, adding: "It's been exciting to be part of a much-hyped battle and they definitely deserve congratulations."
Thanking all the fans who bought his single, he said: "This time last year I never thought for one minute that I'd win The X Factor, never mind about having a debut single out, so I'm just delighted to be in the charts.
CHART ANALYSIS
Colin Paterson
Colin Paterson, BBC News entertainment reporter
It is simply one of the biggest shocks in chart history.
The common belief was that the race for Christmas number one had been destroyed by the X Factor.
For the last four years the winning act has been top of the festive charts by a landslide. Bookmakers only took bets on who would be number two.
This year the corporate might of Simon Cowell has been defeated by a husband and wife's Facebook campaign.
The result is 'Killing In The Name', which most parents would be pretty reluctant to play to their children. It contains 17 uses of the F-word.
This chart shock is right up there with Spiller's 'Groovejet' derailing the start of Victoria Beckham's non-Spice Career in 2000 or crooner Engelbert Humperdink ending The Beatles' run of 11 number ones in a row.
Two other points - this could become an annual event - the public deciding on a track with which to take on the X Factor winner.
Secondly there is still every chance Joe will reach number one next week.
The Rage Against Machine campaign was designed for one week only so Joe could get the top spot, saving him the indignity of being the first ever X Factor winner not to hit number one with their debut single.
Have Your Say: What does Rage's victory mean for X Factor?
"It's been such an incredible couple of months and I got the best Christmas gift I could ever have asked for in winning The X Factor."
Despite earlier in the week calling the campaign "stupid", X Factor judge Simon Cowell offered his congratulations to the couple behind it, Jon and Tracy Morter.
He said: "I am gutted for Joe because a number one single meant a lot to him but I have to congratulate Jon and Tracy, who started the Facebook campaign.
"I called Jon on Saturday to congratulate the two of them that, win or lose, they turned this into a very exciting race for the Christmas number one.
"I am proud of Joe - he worked really hard this week, but he has a great year ahead of him."
The Los Angeles rock band's hit also set two records: it is the first single to reach the top of the charts on download sales alone and has achieved the biggest download sales total in a first week ever in the UK charts.
McElderry's song was only released digitally after his victory in the X Factor, giving it less time to rack up sales than Rage Against The Machine.
On Friday the band's lead was just 9,000 copies, but sales then soared by 200,000 to secure victory.
Official Charts Company managing director Martin Talbot said: "Congratulations to Rage Against The Machine on their number one - as we have seen in recent years, overhauling any X Factor winner in the race for the Christmas number one is no mean achievement."
Free concert
Rage Against The Machine are signed to Epic Records, which is part of Sony BMG, the same label as McElderry.
Mr de la Rocha said the band would perform a free concert in the UK in 2010 to celebrate their chart win.
The past four Christmas number ones have all been by X Factor winners; Alexandra Burke's version of Hallelujah last year was one of the biggest selling festive singles ever.
Joe McElderry
Eighteen-year-old McElderry won X Factor last Sunday
Guitarist Tom Morello said it had "tapped into the silent majority of the people in the UK who are tired of being spoon-fed one schmaltzy ballad after another".
He added that proceeds from the single would go to homeless charity Shelter tying in with the Morters' Facebook campaign which includes an online link to give to the charity, raising nearly £70,000 so far.
Gennaro Castaldo, from high street retailer HMV, said it was a "truly remarkable outcome - possibly the greatest chart upset ever".
RECENT CHRISTMAS NUMBER ONES
2000: Bob the Builder: Can We Fix It
2001: Robbie Williams & Nicole Kidman: Somethin' Stupid
2002: Girls Aloud: Sound of the Underground
2003: Michael Andrews feat Gary Jules: Mad World
Band Aid 20: Do They Know It's Christmas?
2005: Shayne Ward: That's My Goal
2006: Leona Lewis: A Moment Like This
2007: Leon Jackson: When You Believe
2008: Alexandra Burke: Hallelujah
What's all the Rage against?
"It's not so much that Joe lost the race - sales of his single have matched those of recent X Factor winners, and he shouldn't take this personally; this is all about the stunning impact of the Rage Against The Machine internet campaign in galvanising music fans to protest against the dominance of the reality show in recent years."
The expletive-laden song is a "powerful protest", he said, adding: "Rage Against The Machine may not be the ideal expression of the Christmas spirit - and many people will have preferred a more appropriate song to top the festive charts, but their anti-corporate message proved a perfect vehicle through which to register such a powerful protest."
The last big Christmas battle on a similar scale was between the Spice Girls' Goodbye and South Park character Chef's Chocolate Salty Balls in 1998. The Spice Girls won with 380,000 to their rival's 375,000.
Despite losing out on the single top spot, Cowell kept a hold on the album chart, with Susan Boyle's I Dreamed A Dream remaining at number one for a fourth week.
The band's single, Killing In The Name, sold 500,000 downloads beating X Factor winner Joe McElderry's The Climb by 50,000 copies to clinch the top spot.
Their success followed a Facebook campaign designed to prevent another X Factor number one.
One retailer said it was a "truly remarkable outcome - possibly the greatest chart upset ever".
'Sterile pop'
Speaking on the Radio 1 chart show, Zack de la Rocha from Rage said: "We are very, very ecstatic about being number one."
He added it was an "incredible organic grassroots campaign".
"It says more about the spontaneous action taken by young people throughout the UK to topple this very sterile pop monopoly," he said.
McElderry, 18, praised the campaign, adding: "It's been exciting to be part of a much-hyped battle and they definitely deserve congratulations."
Thanking all the fans who bought his single, he said: "This time last year I never thought for one minute that I'd win The X Factor, never mind about having a debut single out, so I'm just delighted to be in the charts.
CHART ANALYSIS
Colin Paterson
Colin Paterson, BBC News entertainment reporter
It is simply one of the biggest shocks in chart history.
The common belief was that the race for Christmas number one had been destroyed by the X Factor.
For the last four years the winning act has been top of the festive charts by a landslide. Bookmakers only took bets on who would be number two.
This year the corporate might of Simon Cowell has been defeated by a husband and wife's Facebook campaign.
The result is 'Killing In The Name', which most parents would be pretty reluctant to play to their children. It contains 17 uses of the F-word.
This chart shock is right up there with Spiller's 'Groovejet' derailing the start of Victoria Beckham's non-Spice Career in 2000 or crooner Engelbert Humperdink ending The Beatles' run of 11 number ones in a row.
Two other points - this could become an annual event - the public deciding on a track with which to take on the X Factor winner.
Secondly there is still every chance Joe will reach number one next week.
The Rage Against Machine campaign was designed for one week only so Joe could get the top spot, saving him the indignity of being the first ever X Factor winner not to hit number one with their debut single.
Have Your Say: What does Rage's victory mean for X Factor?
"It's been such an incredible couple of months and I got the best Christmas gift I could ever have asked for in winning The X Factor."
Despite earlier in the week calling the campaign "stupid", X Factor judge Simon Cowell offered his congratulations to the couple behind it, Jon and Tracy Morter.
He said: "I am gutted for Joe because a number one single meant a lot to him but I have to congratulate Jon and Tracy, who started the Facebook campaign.
"I called Jon on Saturday to congratulate the two of them that, win or lose, they turned this into a very exciting race for the Christmas number one.
"I am proud of Joe - he worked really hard this week, but he has a great year ahead of him."
The Los Angeles rock band's hit also set two records: it is the first single to reach the top of the charts on download sales alone and has achieved the biggest download sales total in a first week ever in the UK charts.
McElderry's song was only released digitally after his victory in the X Factor, giving it less time to rack up sales than Rage Against The Machine.
On Friday the band's lead was just 9,000 copies, but sales then soared by 200,000 to secure victory.
Official Charts Company managing director Martin Talbot said: "Congratulations to Rage Against The Machine on their number one - as we have seen in recent years, overhauling any X Factor winner in the race for the Christmas number one is no mean achievement."
Free concert
Rage Against The Machine are signed to Epic Records, which is part of Sony BMG, the same label as McElderry.
Mr de la Rocha said the band would perform a free concert in the UK in 2010 to celebrate their chart win.
The past four Christmas number ones have all been by X Factor winners; Alexandra Burke's version of Hallelujah last year was one of the biggest selling festive singles ever.
Joe McElderry
Eighteen-year-old McElderry won X Factor last Sunday
Guitarist Tom Morello said it had "tapped into the silent majority of the people in the UK who are tired of being spoon-fed one schmaltzy ballad after another".
He added that proceeds from the single would go to homeless charity Shelter tying in with the Morters' Facebook campaign which includes an online link to give to the charity, raising nearly £70,000 so far.
Gennaro Castaldo, from high street retailer HMV, said it was a "truly remarkable outcome - possibly the greatest chart upset ever".
RECENT CHRISTMAS NUMBER ONES
2000: Bob the Builder: Can We Fix It
2001: Robbie Williams & Nicole Kidman: Somethin' Stupid
2002: Girls Aloud: Sound of the Underground
2003: Michael Andrews feat Gary Jules: Mad World
Band Aid 20: Do They Know It's Christmas?
2005: Shayne Ward: That's My Goal
2006: Leona Lewis: A Moment Like This
2007: Leon Jackson: When You Believe
2008: Alexandra Burke: Hallelujah
What's all the Rage against?
"It's not so much that Joe lost the race - sales of his single have matched those of recent X Factor winners, and he shouldn't take this personally; this is all about the stunning impact of the Rage Against The Machine internet campaign in galvanising music fans to protest against the dominance of the reality show in recent years."
The expletive-laden song is a "powerful protest", he said, adding: "Rage Against The Machine may not be the ideal expression of the Christmas spirit - and many people will have preferred a more appropriate song to top the festive charts, but their anti-corporate message proved a perfect vehicle through which to register such a powerful protest."
The last big Christmas battle on a similar scale was between the Spice Girls' Goodbye and South Park character Chef's Chocolate Salty Balls in 1998. The Spice Girls won with 380,000 to their rival's 375,000.
Despite losing out on the single top spot, Cowell kept a hold on the album chart, with Susan Boyle's I Dreamed A Dream remaining at number one for a fourth week.