Manchester United stars took to Twitter to celebrate notching a fifth successive win.
Manchester United recorded their fifth win in a row to move into third position in the Premier League.
The Dutchman scored in each half, helping United to another vital away win, and leapfrog the Saints in the table in the process.
United registered only three shots at goal in total in comparison to Southampton's 15, but Van Persie's clinical finishing was the difference.
Southampton held more possession with 54 per cent and had five corners compared to United's one. Up next for United are rivals Liverpool - who are now seven points behind, and sit in ninth place.
Manager Louis van Gaal told ManUtd.com after the game: "We didn’t give a lot away in the second half, maybe four chances, but Southampton were the better team.
"We were the lucky team. But I think it is a good signal (that we won)."
Two stars who played in the game took to Twitter to celebrate the win:
They were not the only stars to do so, with injured Daley Blind and Rafael da Silva sending messages of support, along with youngster Andreas Pereira: