With further cause for celebration, off went a flare in the Scoreboard End and van Persie twice sought to double United's advantage before the break, first unleashing a piledriver which Tremmel did well to smuggle wide, then curling well over with a right-footer when Scholes was well placed.
Swansea emerged for the second half on the front foot, and drew level within four minutes of the restart. A sustained spell of pressure culminated in Nathan Dyer crossing from the right, and Michu reached the ball ahead of the diving Phil Jones and flicked an unstoppable finish past De Gea.
Dander up, Swansea quickly pressed for the lead and Wayne Routledge almost provided it, stabbing just wide after a neat one-two with Michu. Although United steadied and began chasing the lead once more, another quick counter from the visitors led to Pablo Hernandez bringing a sharp stop from De Gea. Welbeck's cross was minimally ahead of Chicharito's desperate lunge as the Reds aimed to capitalise on a poor Swansea clearance, but attentions quickly switched back to one of the day's departing heroes as Scholes left the fray to a rapturous reception.
The midfielder was joined by Welbeck in making way for Anderson and Antonio Valencia, and the Brazilian was quickly in the thick of the action, crossing for Chicharito to head wide, via a deflection, then drilling a low volley just off-target with Tremmel beaten. It took brave, last-ditch defending from Jones and Vidic to prevent Flores from turning home on two occasions in quick succession as Swansea continued to play in free-spirited fashion, but Vidic almost pinched the points with a back-post header which sneaked wide of Tremmel's goal.
It was, rather, the Serbian's central defensive partner Ferdinand who had the game's final say, taking advantage of poor defending by lashing home at