Louis Van Gaal was hoping to start his career at Old Trafford on a bright note, but Monk's men had other ideas. The Welsh team took the lead through Ki Sung Yueng in the 28th minute against the run of play. Phil Jones forced Lukasz Fabianski to make a great safe in the first half.
The Red devils were not too impressive and didn't show the sign of a team that is ready to make the top four at the end of the season. Javier Hernandez, Juan Mata and Wayne Rooney were on the starting line up, but Swansea didn't give them the chance to create clear cut chances.
It was a match that witnessed just four corner kicks that were taken by the home side. The last time United lost a match on the opening day of the league was in 1972. While the Welsh team also claimed their first victory over their fancied hosts for the first time in 83 years.
The former Dutch manager deployed a 3-5-2 formation that also featured Ashley Young. The Englishman later got injured and was replaced by Lingard.
After the restart, Rooney got the equaliser for the home side. The captain scored via a scissors kick to revive the hope of the Old Trafford faithfuls. He was denied a brace when his free kick came off the crossbar,
Gylfi Sigurdsson scored the winning goal for Swansea after United defenders failed to take clear their lines.
Garry Monk's men recorded the first three points of the new season.