TEAMtalk looks at why both sides were left with major worries after Manchester United's 4-3 win at Reading in the Premier League on Saturday.
After the win at the Madejski, United boss Sir Alex Ferguson was quick to condemn his side's defending. In fact, he called it the worst of the season - which is saying something in what has already been a poor year for his backline.
Indeed it is hard to think in recent times of a United defence more likely to concede goals. Ferguson does realise this though.
Reading may have ran United close - but the defence on offer from the Red Devils is far from the norm and they should really have pushed them harder.
After an excellent first half, Reading rarely came close, as they almost seemed to realise their chance to take something from the game had gone.
Here, Graeme Bailey looks at the game's major talking points.
Reading named an unchanged side, which meant still no place for Russian Pavel Pogrebnyak. Jason Roberts and Adam Le Fondre continued up front. Danny Guthrie did return from injury to make the bench.
Manchester United made three changes with Ashley Young coming in to form a front three with Robin van Persie and Wayne Rooney, whilst Rio Ferdinand and Darren Fletcher also returned.
Reading stuck to their guns of a 4-4-2, but interestingly they swapped Jobi McAnuff and Hal Robson-Kanu, an astute decision - especially given the impact it had on the first half. Robson-Kanu's role was very effective.
Manchester United went with a 4-3-3 with Young and Rooney either side of van Persie but with licence to roam. Anderson was attacking at will, with Fletcher and Michael Carrick sitting. Anderson was replaced by Phil Jones due to injury before half-time but rather than sitting, he was allowed to continue in a similar role.
Reading made all three changes but Noel Hunt and Pogrebnyak were late replacements and made little impact. Garath McCleary made more of an impact but again was fairly late on.
Manchester United's changes were all too different. The first came on the half-hour, and was purely tactical as Rafael, who had been given a tough time, was replaced by Chris Smalling. The Brazilian was less than amused, but Smalling made a difference and helped steady them. Soon after, United were forced to replace the exciting Anderson with Phil Jones, who continued in an attacking role. With 20 minutes left, Danny Welbeck came on for van Persie but made little impact.
Not a great day for Mark Halsey as the one big decision he and his assistants had, they got wrong. Just before half-time, van Persie saw his shot cleared off the line by Shaun Cummings. Van Persie appealed and at the time, it looked over the line. Replays soon showed the shot was clearly over. The argument for goalline technology will continue. Halsey did give a penalty to United, but that was a straightforward decision following a foul by Jay Tabb on Jonny Evans.
Reading clearly miss goalkeeper Alex McCarthy - Adam Federici never looked comfortable in the home goal. Reading's main weapon was wide-men Robson-Kanu and McAnuff, and both performed very well. Nicky Shorey also did well from left-back; his set-pieces particular were excellent. Their midfield schemer Jay Tabb had an off day as he never got going.
A tale of United's season is great in attack and shambolic in defence. Rafael, Evans and Lindegaard were pretty awful. But at the other end they were very good. Anderson had a superb half-hour, before going off, whilst Rooney and van Persie showed their understanding is there - and they scored three times between them, yet they still look as if there is more to come.
Reading will take plenty from this match, they won't be the only side to ship goals to United. But defensive-wise, McDermott will know they need to impress more.
Ferguson admitted that United's defending was the worst he had seen this season, yet they still won - the tale of their season you could argue. But they sit three points clear at the top of the table at the start of December without hitting their stride fully. The signs are good - well, better than their defending at least...