Having somehow dug out positive results despite far from convincing performances throughout much of the season, at the Liberty Stadium on Saturday Manchester United managed to conjure up the reverse. A more fluid display than has been seen through much of Louis van Gaal’s debut campaign looked to be getting its rewards when a flowing team move produced an opening goal for Ander Herrera just before the half-hour mark.

But less than two minutes later their defensive frailties repapered to allow Sung-Yueng Ki, who scored in Swansea’s opening-day win at Old Trafford, to score. And things got worse still for visitors when Jonjo Shelvey’s pile driver deflected in off the head of Bafetimbi Gomis 17 minutes from the end.

The defeat was just Manchester United’s second in their last 20 matches in all competitions. A large portion of those results have come despite uninspiring displays and with some curious tactical choices from Van Gaal. At the Liberty Stadium, he did what many fans had been calling for for some time by inserting Spanish playmaker Herrera into midfield and putting Wayne Rooney up front.

While still far from a complete performance, United controlled the second half and were certainly much improved from their defeat to the same opponents in Van Gaal’s competitive debut. Yet the veteran Dutch coach will know that all that matters this season is earning a return to the Champions League. In that aim, this defeat could prove mighty costly. For the time being United drop behind Arsenal into fourth, and with fifth-placed Southampton, just a point back, are still to play tomorrow. For Swansea, it is a welcome three points after their struggles following Wilfried Bony’s sale to Manchester City last month.

Swansea could have been ahead in the opening five minutes. First the returning Gylfi Sigurdssson had a shot blocked from Marcos Rojo. And then from the resulting corner Herrera was forced into a far more desperate intervention to prevent a goal, when sticking out a leg to prevent Gomis’ free header from six yards finding the net.  

Two minutes before the half-hour mark, Herrera was to make a substantial contribution at the other end. Manchester United produced the type of combination play that has been so sorely lacking this season when working the ball forward and across Swansea’s box, with skilled contributions from Luke Shaw, Wayne Rooney and Angel di Maria. From the Argentine’s perfectly weighted pass, Herrera struck a beautifully deliberate effort into the bottom corner of the net, possibly with the aid of the slightest of touches off Ashley Williams.

The scene looked set for United to go on and produce one of their more complete displays of the season. Instead, within two minutes of going in front they were hauled level. Defensive responsibilities were left unfulfilled both out wide, to allow Jonjo Shelvey to deliver a cross from the left, and then in the heart of the penalty area as Ki swept in first time from six yards.

United bounced back to dominate play in the second half, yet they failed to make it count. The closest the visitors came to going back in front being when Marcos Rojo headed over Di Maria’s corner. And they were cruelly punished with a fortuitous winning goal for a Swanse team that had won just once in five games since Bony’s exit. Shelvey’s shot from distance was hit with some force, but, despite the striker trying to duck out of the way, it hit the head of Gomis to take it beyond the dive of De Gea.

Facing the possibility of being bumped from the top four by the end of the weekend, Van Gaal will doubtless take a horrid performance if it yields the three points at home to Sunderland in a week’s time. They may, though, have to do it without Van Persie, who was seen leaving the Liberty Stadium on crutches.