Goals in both halves from Ryan Seager were enough for The Saints as United lost for the third time this season.
Southampton opened the scoring just before the half hour mark when Seager latched onto a chipped through ball and turned before firing past Gollini. Sam Byrne almost equalised for United before the half was out, forcing a save from Southampton’s keeper at his near post, but United went into half time behind.
Southampton doubled their advantage almost instantly after the break when another ball over the top caught United out, and Seager popped up to put the ball past Gollini at his ner post.
At 2-0 down United seemed to start clicking and Perreria almost brought United level, but was stopped by a last ditch tackle in the 6 yard box. But he got his goal on the 73rd minute cutting in and firing past Southampton’s keeper from the edge of the box.
United looked for an equaliser but it was Southampton that went closest before sealing their win when Seager fired over from close range.
United drop to second behind Southampton after their third defeat and will look to get back to winning ways against Tottenham at Carrington next week.