Manchester United 0 Southampton 1

The last time Southampton won a league match at this ground was in 1988, when Colin Clarke scored both the goals. But a lot of teams have rid themselves of that kind of long, undistinguished record at Old Trafford over the last couple of seasons. Swansea have picked up their first-ever win here and Newcastle their first since 1972. West Brom's victory here last season was their first since 1978 and Everton had not managed it since 1992. The old place just doesn't scare opponents in the way it once did and Southampton – this brilliant story that could go all the way to the Champions League – are the latest to face Manchester United and bury a hoodoo.

They won courtesy of Dusan Tadic’s second-half goal, six minutes after being introduced as a substitute, and another demonstration of why Ronald Koeman’s side has the most parsimonious defence in the top division. In the process, it takes them above United into third position and their supporters could be forgiven for gloating bearing in mind the coverage during that exodus of players last summer. “Where have all our players gone?” they sang. All that has happened is they have new heroes now and it might just be that they are even better than the last lot.

For United, perhaps it was a reality check. Louis van Gaal has been emboldened enough recently to talk about United still being genuine title contenders but it never felt realistic and it must alarm him that a team with Robin van Persie, Wayne Rooney, Angel Di Maria and Juan Mata could be so ineffective in attack. Van Gaal could not even find room in his squad for Radamel Falcao, opting instead to have the teenager James Wilson on the bench.

Yet when Di Maria was substituted and Van Persie injured the player who was brought on to play in attack was Marouane Fellaini and it suddenly felt as though United, the team that used to be famed for their late feats of escapology, were pinning their hopes on a high ball into the box.

The worrying thing for Van Gaal is that the lack of refinement has become a recurring theme for his side. Even so, it was strange to see the frequency with which a player of Di Maria's gifts wasted possession. There is always a flicker of apprehension inside Old Trafford whenever Phil Jones or Chris Smalling are expected to bring the ball out of defence and their inadequacies will always encourage opponents. Smalling had charged out of defence in the moments preceding Tadic's goal and did not get anywhere near the ball. Once again, it felt very apparent that United have neglected this area of their team.

Tadic had replaced the peripheral Eljero Elia and it was a wonderfully subtle pass from him to create the danger in the first place. His reverse pass left Graziano Pell e clear, inside the penalty area, and David de Gea badly exposed in the home goal. Pelle's shot came back off the post and fell obligingly for Tadic to keep his nerve when others might have been tempted to blast the ball.

Southampton had shown right from the start that they fancied their chances and were encouraged, perhaps, by the first communication breakdown between Smalling and De Gea inside the opening minute. Shortly afterwards, Nathaniel Clyne pinged a shot just wide from one of those overlapping runs from full-back and already it had become apparent that Southampton would play, as they have done virtually all season, with no sense of inferiority.

For the rest of the first half, however, they did not pass the ball with enough creativity to threaten De Gea seriously. Van Gaal was operating with his least orthodox system yet – a 3-3-2-2 wing-back formation with Danny Blind replacing Jonny Evans among the centre-backs and Di Maria operating alongside Van Persie – and again it was tempting to think they look more comfortable playing with a straight back four.

What they really lacked, however, was penetration. Too often the passing lacked any real thrust. It was a slow tempo and there was carelessness, too, such as the moment when Di Maria had a free-kick in a position to whip the ball into the penalty area and did not just commit the cardinal sin of failing to get it past the first man but barely got the ball off the ground.

Southampton had lost Toby Alderweireld from their defence due to an early injury and it must have been startling for Van Gaal, just like the corresponding fixture at St Mary's last month, to see his team lacking any real spark. Van Persie won the game for United on that occasion with his best performance of the season, but he lasted only an hour this time.

Wayne Rooney then pushed further forward, with the substitute Ander Herrera taking his place in midfield, and Fellaini soon joined him. Yet the late onslaught that might have been expected never really materialised. United just aren’t that kind of team any more.