A disciplined Real seemed content to sit back against a tame Liverpool who carried little threat for most of the game.
Although the UEFA initially blamed the Merseyside club's fans for the mayhem, the governing body later apologised following the release of an independent review.
Liverpool's previous biggest win over United was a 7-1 victory in 1895.
Goals from Victor Osimhen and Giovanni Di Lorenzo gave dominant Napoli a 2-0 victory at 10-man Eintracht Frankfurt in their last-16 first leg.
Youngsters around the world had immersed themselves in the Beatle mania when John Lennon, Paul MacCartney, George Harrison and Ringo Starr came to India in 1968.
The match ended goalless after Kai Havertz' early strike was flagged offside by VAR.
Audio of a woman moaning was played at high volume just as host Gary Lineker was seeking the opinion of fellow pundit Alan Shearer ahead of Liverpool's 1-0 win over Wolverhampton Wanderers.
Messi's PSG will take on German giants Bayern Munich.
Arsenal edged Chelsea 1-0 to move back into Premier League summit.
The Norwegian striker scored a brace in a 3-1 win for Pep Guardiola's side.