Ronald Koeman sucked Louis Van Gaal into playing right into his hands and the end result was Saints first ever Premier win at Old Trafford.
The less charitable of those connected with Manchester United including their manager Louis Van Gaal and star millionaire Wayne Rooney will point to the possession that their team had and claim that Saints did not deserve a draw being pinned back for so long.
But Ronald Koeman had noticed that United were not as good going forward as some miht claim, that their play was very one dimensional and morever Saints were more than capable of dealing with it.
United's play relies on pace down the flanks, one of our strengths is the our two full backs Nathaniel Clyne and Ryan Bertrand they were going to have to excel themselves if they were to beat these two.
Koeman would also have noticed that Luke Shaw is no wing back, Shaw is an excellent defensive full back as he showed when putting in a magnificent block tackle on Pelle when the Italian looked certain to score, but going forward Shaw flatter to deceive.
Time after time United would feed the ball to Shaw who would run at Clyne however time after time the ex Saints would fail to beat his man and more often then not stop and turn back and pass it backwards.
Hen Shaw did get the opportunity to cross he rarely found a United player, poor crosses went straight to our central defenders who dealt with them easily, the same happened on the other flank where Valencia fared just as badly as Shaw.
The wily Dutch manager (and for the record here I do mean Koeman rather than the one who seems to have wasted £200 million) knew that United couldn't change their style of play and if we kept their wide men quiet then we would have a grip of the game.
In the centre of the park it was the same with our players fighting for every ball and never giving up chasing and carrying, United did not like it and it threw them out of their rythym.
Having seen his team put his game plan into effect brilliantly it only now remained for the coup de grace to be applied, the pundits on Sky agreed the game turned on the substitutions, they conveniently forgot that we lost our best player of the season so far with injury and failed to lay blame on Van Gaal who effectively only had a plan B of lumping it up the middle in the final half hour.
Koeman though was out to win the game, bringing on Tadic was perhaps not the obvious choice, with Saints conceding possession to United they might have thought that Shane Long's pace and work rate might be best employed but Koeman had other ideas and proffered the guile of Tadic and tis proved to be a master stroke with the Saints sub being instrumental in the build up to the goal and finishing cool for the winner.
From then on it was a matter of keeping on dealing with United's one dimensional play, late on there was the odd scare but the fact was that for the first time in 6 years United had not had a shot on target on their own turf and that is something to praise.
But although Saints conceded possession they did not concede much else, their 9 shots was only 1 less than United's 10, their 1 on target was still more than United's 0 and their 5 corners 2 more than United, showing that defensively Saints were not in trouble very often.
All in all it was a classic piece of managerial nouns from Ronald Koeman who again showed he has the knack of not only having plan B's C's, D's and got knows how many more, but he has the skill to put them into effect at different times in the game.
Of course Wayne Rooney and co are annoyed, they have been beaten at their own game and now know the feeling that they enlisted on many sides over the past decade or more.