Liverpool moved top of the Premier League as they outclassed Manchester United at Anfield and dented the visitors' hopes of a top-four finish.
Liverpool, who started a point behind Manchester City, led when Luis Diaz stroked in Mohamed Salah's low cross.
The home side continued to dominate and Salah slotted in a deserved second from Sadio Mane's reverse pass.
United showed slight improvement before Mane swept in a third and Salah's deflected effort sealed a routine win.
After their 5-0 win at Old Trafford in October, Liverpool are the first club to score at least eight Premier League goals against United in a single season.