Sam Bailey, a prison guard who won this year's version of the British talent show "The X Factor", took the Christmas number one position on the UK singles chart with her debut release on Sunday.
The 36-year-old mother-of-two sold 149,000 copies of "Skyscraper", a reworking of American singer Demi Lovato's 2011 hit, outselling U.S. singer Pharrell Williams' "Happy" by more than two to one.
Last week's number one, "Somewhere Only We Know" by British singer Lily Allen, slipped to number six. The song received wide exposure as the theme for a Christmas television advertisement.
"Being number one is absolutely amazing," Bailey said. "It really is the icing on the cake."
Two social media campaigns designed to keep the "X Factor" winner off the top spot, cast by their supporters as an attempt to promote real music rather than manufactured acts, ended in failure.
Fans of the heavy metal group AC/DC pushed the 1979 song "Highway to Hell" up to fourth place, giving the band their first top 10 British single of their 40-year career.
In the second organised campaign, the British dance act Altern 8 saw their 1990s hit "Activ 8 (Come With Me)" reach only 33rd place, according to the UK Charts Company, which compiles the weekly list.
On the album chart, British singer Robbie Williams' "Swings Both Ways" held on to the number one position, ahead of boy band One Direction's "Midnight Memories".