Mario Balotelli had to be held back by Liverpool supporters after being involved in a fracas with Chris Smalling.
The combustible Italian had already been booked and Reds fans, fearing another sending off after Steven Gerrard's 45th minute dismissal, stepped in and intervened.
Manchester United sealed a vital 2-1 victory, courtesy of two wonderful goals from Juan Mata, while Balotelli may have been saved from appearing on the back pages by Gerrard's antics.
Smalling believed he had challenged the former Manchester City man fairly, but he ended up buried in the stands.
Balotelli managed to curb his enthusiasm towards the United defender but was unable to score an equaliser for Brendan Rodgers' side.
The Reds are now five points adrift of their rivals in the hunt for a Champions League spot.
Independent News Service
The great Pele had not returned to his seat in the directors' box and the digital clock by the corner of the Kop had not been restarted for the second half, so, in some ways, you could say that time really did stand still for Steven Gerrard's moment of madness.