The Reds fell behind when Hal Robson-Kanu finished at the far post but soon leveled thanks to Anderson's fine strike and a Wayne Rooney penalty.
The Royals reclaimed the lead through Adam Le Fondre and Sean Morrison, before Sir Alex Ferguson’s men turned the game around via Rooney’s second and a slick Robin van Persie strike.
Although it was a stuttered and inconsistent display, there were several impressive performances. Here, I assess United’s 14 featured players.
Anders Lindegaard: Once again preferred to David De Gea, the Dane endured a disappointing first half and perhaps should have done more to prevent Reading’s second and third goals, which both came from set pieces. His second half performance was more assured, but underwhelming. (6/10)
Rafael: Although arguably United’s best player this season, the young Brazilian struggled against the physical threat that came from the Royals’ left wing and was dragged off for Chris Smalling in the first half. Clearly angered, the defender cut a frustrated figure in the United dugout. (6/10)
Rio Ferdinand: Recalled to the starting XI in place of Chris Smalling, the veteran defender will have been disappointed to concede twice from set pieces considering his usual aerial ability. He showed the occasional lapse in concentration, but on the whole was quietly competent. (6/10)
Jonny Evans: The Irishman was at fault for Reading’s opening goal when his attempted clearance fell to the feet of Hal Robson-Kanu, who finished to great acclaim. After that, Evans had a decent game and executed a couple of excellent tackles, although his set-piece defending was poor. (7/10)
Patrice Evra: Typically ambitious down the left flank, the Frenchman created several opportunities by bombing ahead alongside the improved Ashley Young. Like the rest of his defensive teammates, the stand-in captain was defensively suspect, particularly from set piece situations. (8/10)
Michael Carrick: Playing as one third of a midfield trio, the Reds veteran was typically competent in his passing and distribution of possession, but lacked conviction at times. His vision did inspire Robin van Persie’s goal, however, playing a ball from deep from which Rooney gathered an assist. (6/10)
Darren Fletcher: Starting his second Premier League match this season, the Scotland captain covered lots of ground and looked stronger than on previous outings. His passing was disappointing, however, with several wayward attempts gifting possession back to Reading. (6/10)
Anderson: Having maintained his starting place following an excellent performance against West Ham, the Brazilian continued his upward momentum by netting brilliant first half goal with his delightful left foot. Frustratingly, his match was cut short by a hamstring injury. (7/10)
Ashley Young: The former Aston Villa man is much maligned at Old Trafford this season, though the Reds winger produced a surprisingly effective performance on Saturday evening, and he will be pleased with his display. One sour note is his increasingly predictable cut inside from the left. (8/10)
Wayne Rooney: With just four goals to his name prior to kickoff, United’s star striker will be delighted to increase his tally by 50 percent with two well taken strikes. The England international was a constant threat, playing behind van Persie, and showed his immense passing ability at times. (9/10)
Robin van Persie: Saturday’s match was a strange one for the Dutchman, despite netting a fine first half goal. Although a second was wrongfully deemed not to have crossed the line, RvP should have increased his tally after the break and was guilty of missing two excellent chances. (8/10)
Chris Smalling: The former Fulham man was introduced as a replacement for Rafael before the break as Sir Alex opted for height against Reading’s powerful attacking threat. In the end, Smalling did well and looked dangerous going forward, though his decision making was questionable. (7/10)
Phil Jones: The returning utility man replaced the injured Anderson shortly before half-time and will be pleased to get more minutes under his belt. As ever, he showed great spirit and adventure going forward, producing a competent display. (7/10)
Danny Welbeck: United’s home grown striker came on for van Persie with time running out whilst Reading were applying pressure. Although he had little time to influence the game, his composure on the ball helped the Reds see out a crucial win in the south. (6/10)