target as the hosts pressed but the Gunners responded with De Gea superbly stopping a van Persie volley and Arshavin firing wide when Smalling was caught up the pitch.
Tom Cleverley shot weakly at Szczesny after a brilliant one-two with Young and Nani failed to convert a cross from the former Aston Villa winger but the dam broke again when Rooney repeated his free-kick feat in the first half by whipping home for 4-1 and becoming United's all-time record scorer in the Premier League.
Smelling blood, Smalling tore forward and ignored Phil Jones on the overlap to instead feed Rooney, who prodded through for Nani to net with the most outrageous of cheeky finishes. Nani then made way, along with Anderson, for Ryan Giggs and Park but the relentless attacking continued.
Rooney wedged a golf-like shot of sheer class against an upright before Park exchanged passes with Young to bury a low finish into the corner of the net. Van Persie restored a semblance of pride with emphatic finish after being played onside by Jones but United simply stepped up a gear again.
Jenkinson received a second yellow card for bundling Javier Hernandez over when he was through on goal and there were more illegal tactics used to halt the red tidal wave when Walcott tripped Patrice Evra inside the box. Rooney stepped up to seal his hat-trick with a confident