Manchester United Swansea Sigurdsson De Gea
Swansea midfielder Gylfi Sigurdsson scores the winner past Manchester United goalkeeper David De GeaReuters

Louis Van Gaal – the messiah, the man who can turn everything around again and bring back glory to Manchester United, and make that David Moyes reign look like a mere blip in this massive club's history – was set up to begin his reign in the best most explosive possible manner, with Swansea City set to be the first casualty.

Well, after the first 90 minutes of football under Van Gaal at Old Trafford, the only aspect that remains clear is that the Dutchman has plenty of work to do, if he is to turn Manchester United into English Premier League title contenders.

Because in the opening match of the Premier League season, the result wore an all-too familiar under-Moyes-reign look – plenty of effort, a few positives, but the end result not quite going their way.

Swansea were the team that turned that "Van Gaal makes an incredible start to his Manchester United career" script inside out, with goals from Ki Sung-yueng and Gylfi Sigurdsson giving the Welsh side a massive 2-1 victory.

Wayne Rooney, the new permanent Manchester United captain, made his mark with a fabulous goal, the equaliser in the second half that gave his team hope of fashioning a come-from-behind victory, but a consolation goal it ended up being as Sigurdsson struck late in the game to give Swansea a stunning three points.

It was never the kind of game where you look up at the clock and realise 30 minutes of the match has gone, and then another few more flying away. The pace was considerably slow, with Swansea setting up quite well, sitting behind and allowing United plenty of position in their own half, while ensuring the home side could not waltz their way through in the final third.

Van Gaal was always going to play a 3-5-2 or a 3-4-1-2 formation, with two youngsters – Tyler Blackett, who looked quite composed, and Jesse Lingard, who would see his afternoon ended prematurely through injury -- handed their debuts, and that meant plenty of possession in the first third of the pitch, with very little penetration in the area that matters.

Swansea were inconsistent on too many occasions under Garry Monk last season, but this time around they seem like a much more well-drilled unit, with every single player perfectly aware of his responsibility.

The first real opportunity, despite all of the Manchester United possession, was created by Swansea, with Gylfi Sigurdsson, back in the white shirt of the Welsh side, taking a shot from just outside the box, which was comfortably gathered by David De Gea.

Wayne Rooney, immediately at the other end, took a similar effort, which did not remotely trouble Lukasz Fabianski, making his Swansea Premier League debut following his summer move from Arsenal.

United's new signing Ander Herrera just could not get into the game enough, even if there were a couple of neat passes, which showed you the kind of player that he is, with Juan Mata, playing just off the top two of Wayne Rooney and Javier Hernandez, also unable to have enough of an impact, with the Spaniard looking the most dangerous when delivering setpieces.

Swansea did look capable of finding a goal on the break, with United's defence clearly looking like their Achilles heel, and they did on 28 minutes, with Sigurdsson laying the ball off for Ki, who, given the freedom of Old Trafford just outside the area, stroked the ball in after Wilfried Bony intelligently blocked Phil Jones' desperate attempt to thwart the effort.

Manchester United did not really respond after the first goal, with the game just petering out into halftime, before everything changed.

Van Gaal would have given his own hairdryer treatment in the dressing room, and it seemed to work, with United coming out much the brighter in the second 45. The fact that the manager went into a flat back four with traditional wingers in Adnan Januzaj and Nani coming in might have also helped, but whatever the reason, United looked like a completely different team in the second half, driving forward with much more purpose and inevitably finding the equalising goal.

Wayne Rooney Manchester United Swansea City Fabianski
Wayne Rooney looked like he had sparked a Manchester United comeback with this brilliant goal, before it all went horribly wrong againReuters

Seven minutes into the second period, and captain fantastic Rooney had his goal. It was off a corner, won by Januzaj, who was terrorising Neil Taylor on the United right, with Phil Jones winning the initial delivery on the near post, allowing Rooney to bicycle kick the ball into the net from four yards.

Manchester United now looked like the team who could go on and win the opening match of the season, with Rooney suddenly looking in the mood, nearly opening up the Swansea defence, before seeing a wonderful freekick from 22 yards graze off the post and wide with Fabianski well and truly beaten.

The Premier League, though, is the most thrilling competition in the world, because you never know what's going to happen. Just when it looked like there was only going to be one winner, in came Swansea with the sucker-punch.

Bony, who worked tirelessly without too much service up top, won a freekick just inside the United half, and took the setpiece quickly, allowing Sigurdsson to find substitute Jefferson Montero on the left. The new Swansea man sprung forward before picking out Wayne Routledge perfectly on the far post. The Swansea winger miskicked his effort on the volley completely, but the ball fell perfectly to Sigurdsson in the middle of the penalty box, with the Iceland international forcing the ball past De Gea with his left foot.

With 18 minutes to go, United needed at least one goal, and press and probe desperately they did, with Marouane Fellaini throw into the mix to make use of his physicality and height, but Swansea would not be denied as they stood firm to grasp a famous victory.

Plenty of work for Van Gaal to do, especially at the back – some signings are necessary and quick, otherwise this season might just get away from them.

Other results: Leicester City 2-2 Everton; QPR 0-1 Hull City; Stoke City 0-1 Aston Villa; West Brom 2-2 Sunderland; West Ham 0-1 Tottenham.