It is more than just his 26 goals. It is occasions like this when Ibrahimovic commands the stage as only a giant of the game can. It does not matter how well his team are playing. It is irrelevant who deserves what. Zlatan decides.
And yesterday he decided the first major trophy of the season should go to United.
He decided the Community Shield should be theirs in August, too - and Jose Mourinho counts that. He bought him to make the difference and he has not disappointed. Mourinho always knew what United were getting in Ibrahimovic; now the rest of the country does, too.
He is great, make no mistake. He scored a great free-kick to put United ahead against the run of play and his goal that won the match - after Southampton had fought back - was great, too.
Started by Ibrahimovic, finished by him as well.
He is a target man in the truest sense of the term, always showing, always offering the out ball when his teammates are pressed. A leader, too. It was noticeable when Jesse Lingard scored United's second, he immediately shared the joy with Ibrahimovic. It is as if he has become the father figure for the younger United players, the way Eric Cantona was to a previous generation.
Yet it would be harsh to make it so much about one man when Southampton were a huge part of this game. Arguably, they deserved to win. Southampton endured a trio of setbacks in the first half that would have crushed a lesser side. Instead, from 2-0 down, and having had a good goal disallowed, they stood level on 48 minutes.
But it was Ibrahimovic who had the last word.
Just as Mourinho was briefing Wayne Rooney on the sideline, United cleared and broke. Ibrahimovic took the ball, knocked it some way ahead to gain distance, but knew he could not win the foot race. So, he laid it off.
Did he then sprint into the box? No, he's too smart for that. He watched United build the pressure. Martial held on to the ball and made progress, gamely. He laid it out to Herrera.
Having started his run into the box moments earlier, the striker timed his run to perfection to meet a cross with a header that left Forster no chance.
Mourinho told Rooney to sit down. Ibrahimovic stayed on and Mourinho collected his 11th cup win in 13 finals.
"Zlatan gave us the cup," he said, as his players cavorted with the trophy.
Southampton might not have deserved to lose, but Ibrahimovic deserved to win. And, special player that he is, he was happy to carry United along with him. Daily Mail