For decades, this sporting rivalry, borne as a result of neighbouring cities enjoying industrial booms in decades gone by, has been one of the standard-bearers of the English top flight.
Dramatic late goals, red cards, on-pitch brawls and managerial arguments—this fixture has seen it all, and the rivalry between the two sets of fans is one which is bettered by few others throughout the world.
Some supporters of these two clubs see the fixture as the biggest rivalry of the domestic season, while others place the local derby higher—Manchester City vs. United, Liverpool vs. Everton.
Perhaps so, but there is no denying the depth of feeling that goes into this particular matchup.
Here are four worldwide rivalries which can lay claim to being up there with United-Liverpool in terms of fan feeling, importance or coverage.