It is the night when Liverpool fans will do the unthinkable - want bitter rivals Manchester United to win.
United host Manchester City at 20:00 BST in a game that will define the Premier League title race.
Liverpool are two points ahead of City, but if Pep Guardiola's side can beat their neighbours and win their game in hand. they will go a point in front with three games remaining.
Reds midfielder James Milner, a former City player, says it will be the "first time" in his life that he will support United.
But what of United fans? A win will end a wretched run of results and keep up their hopes of a top-four finish, but it will also hand Liverpool the initiative as they chase their first league title since 1990. Do some supporters actually want their team to lose?
We want Liverpool and United fans to get in touch and let us know how they are feeling about tonight's match.
And for fans of other teams... let us know if you have ever been in a situation where you have wanted a bitter rival to win, or preferred your team to lose.
Send us your thoughts via this link: https://ssl.bbc.co.uk/sport/contact
You can also tweet #bbcfootball or text 81111.