Ronald Koeman has received many plaudits for Southampton’s exceptional organisation and this was arguably their most impressive tactical display of the season. The Dutchman used an unusual system to disrupt Manchester United’s buildup play, then introduced the matchwinner Dusan Tadic to great effect.

Koeman handed his wide players different responsibilities, creating a lopsided but highly efficient team. The right-sided Steven Davis tucked inside, effectively becoming an extra central midfielder, and cut off passes to Wayne Rooney and Ángel Di María in United’s inside-left channel. On the opposite flank, Eljero Elia was a surprise starter and given freedom to stay up the pitch, offering a counterattacking threat.

Southampton’s area of weakness was the freedom they afforded to United’s wing-backs, because Luke Shaw and, in particular, Antonio Valencia were often in oceans of space. Koeman’s full-backs were brave enough to move forward and engage them, however. Only once, when Ryan Bertrand was cautioned for hauling back Valencia, did this cause problems.

The game was scrappy and short of creativity. The midfielders stuck tight to their opponents and cancelled out one another. Rooney and Juan Mata were forced to drop extremely deep to collect short passes, which meant the next ball was difficult. They were unable to combine regularly with Robin van Persie and Di María, who was deployed in a centre-forward role and unable to exhibit the change of pace which makes him such a dangerous attacking midfielder.

Louis van Gaal was anticipating Southampton’s man-marking in midfield, and therefore gave licence to his three centre-backs to bring the ball forward. This prompted Southampton to move forward from their deep shape and confront the man in possession, and briefly opened up space for United to attack into, but Morgan Schneiderlin and Victor Wanyama covered for one another excellently, screening the defence.

Southampton’s midfielders and forwards initially struggled to combine. After a positive start, Saints found themselves camped inside their own half and therefore played on the counterattack. Their lone centre-forward, Graziano Pellè, came short and needed runners in behind him but only Elia was in a position to support and was rarely involved. It increasingly became obvious that Southampton missed Sadio Mané, who started in a central position against Chelsea and Arsenal, and opened the scoring in both games following quick runs in behind.

Sure enough, the winner came when Tadic and James Ward-Prowse managed to link with Pellè. Tadic converted a rebound from the striker’s shot off a post. Southampton are capable of far better attacking football but, in terms of discipline and result, this was the perfect away performance.