The race for the Champions League qualification places became tighter than ever over the weekend, as United's defeat at Swansea City was capitalised upon by rivals Manchester City, Arsenal and Liverpool.
The Reds loss in Wales leaves United on 47 points, Arsene Wenger's side leapfrogged Louis van Gaal's side into third place, on 48 points, with a 2-1 win at Crystal Palace.
Santi Cazorla's penalty and an Olivier Giroud effort were enough to hold off a late fightback from Alan Pardew's men.
City pulled further ahead on 55 points after they thrashed Newcastle 5-0- Sergio Aguero, Samir Nasri, Edin Dzeko and a brace from David Silva gave Manuel Pellegrini's side their biggest win of the season.
With Chelsea held to a 1-1 draw at home to Burnley in a controversial encounter, City are now five points off the top spot occupied by the Stamford Bridge outfit.
Ironically, the best result of the weekend from a Red point of view was Liverpool's 2-0 win at Southampton.
Although Brendan Rodgers' men cut the gap to United to just two points to move on to 45 points, the result keeps United in the top four, one point ahead of the Saints, who are fifth with 46.
Tottenham missed their chance to move up the table after a late draw with West Ham.
Diafra Sakho and Cheikhou Kouyate gave the Hammers a 2-0 lead at White Hart Lane, but Danny Rose and Harry Kane, with the last kick of the game, salvaged a point for Spurs, who are seventh on 44 points.
With just four points separating Arsenal in third and Spurs in seventh- and United playing Tottenham and Liverpool in March, Manchester City and Chelsea in April, and Arsenal in May, the battle for the Champions League will go down to the wire.
It's all to play for.