But how well did it sell?
Sales data out this weekend has shown that the group notched up 45,000 'combined sales' of their track - an original song written by the group - in its first chart week on sale.
'Combined sales' includes downloads and streaming figures from services like Apple Music and Spotify.
That total makes the song the second lowest selling to date, above only Louisa's from 2015.
Last year's victor Matt Terry had slightly more sales despite charting a place lower.
However, Rak-Su, Louisa and Matt are at a distinct disadvantage over previous winners due to a previous shift in chart week.
In the summer of 2015 the chart moved from the Sunday to the Friday, meaning that the most recent winner singles lose out on almost three full days' worth of sales when they are released at the end of Sunday night.
X Factor winners' singles - first chart week sales
740,000 - Shayne Ward: That's My Goal (2005)
580,000 - Alexandra Burke: Hallelujah: (2008)
570,000 - Leona Lewis: A Moment Like This (2006)
490,000 - James Arthur: Impossible (2012)
450,000 - Joe McElderry: The Climb (2009)
440,000 - Matt Cardle: When We Collide (2010)
280,000 - Leon Jackson: When You Believe (2007)
210,000 - Ben Haenow: Something I Need (2014)
210,000 - Little Mix: Cannonball (2011)
150,000 - Sam Bailey: Skyscraper (2013)
130,000 - Steve Brookstein: Against All Odds (2004)
46,000 - Matt Terry: When Christmas Comes round (includes 11,000 'streaming sales') (2016)
45,000 - Rak-Su: Dimelo (includes 9,000 'streaming sales') (2017)
40,000 - Louisa Johnson: Forever Young (includes 3,500 'streaming sales') (2015)
But it really doesn't matter
While a low selling first single may not be quite the start to an X Factor career one would hope for, success of winner's singles seems to be no indication for how well an act will do.
Little Mix's winner's track failed to make much impact and yet the girls are now one of the UK's biggest acts with a string of chart hits.
On the other hand, the likes of Joe McElderry and Matt Cardle may have sold over twice as much with their winner's singles but couldn't follow them up.