United dominated from the start and were 3-0 up at half-time thanks to Paul Pogba's stunning drive and two goals for Zlatan Ibrahimovic - his first in the league since September. Mike van der Hoorn headed in for Swansea midway through the second half but there was no real danger for the visitors, whose manager Jose Mourinho watched from the stand because of a touchline ban.
United climb up to sixth in the table, while a 10th Premier League match without victory means Swansea remain second from bottom. The Swans' dismal performance prompted boos from the home crowd and left manager Bob Bradley with just one point from his first four games in charge.
But for Mourinho, a second win in eight league matches comes as welcome relief following a difficult few weeks.
Source: BBC Sports