The pair linked well all afternoon, swapping passes in tight spaces and making unselfish runs off the ball to open up space. At one point in the first half, a series of clever interchanges cut through Rovers' defence with such ease that the action resembled a training ground stroll rather than a Barclays Premier League fixture.
Meanwhile, Blackburn struggled to assert themselves on the game. Rafael's close attentions frustrated former Liverpool forward El-Hadji Diouf, while lone frontman Jason Roberts was starved of service from midfield.
Nani tested visiting goalkeeper Paul Robinson at his near post before Christopher Samba almost put through his own net and Berbatov headed wide from a corner.
United were knocking on the door and a second goal duly arrived on 23 minutes. Park carried the ball forward from the inside left channel and fed Rooney on the edge of the area. The South Korean continued his run, Rooney returned the pass and Park, now clean through and with only Robinson to beat, dinked the ball over the Rovers goalkeeper. It was simple, beautiful and devastatingly effective.
Clearly shell-shocked by United's storming start, Blackburn then hit the self-destruct button and gifted United a third goal on 27 minutes. Full-back Pascal Chimbonda didn't look before playing the ball back to goalkeeper Robinson and instead passed the ball straight to Berbatov, who, loitering in the Rovers penalty area, blasted the ball into the net.
Vidic then missed a simple chance to add a fourth, while Nani fired over the bar from distance and Berbatov was denied a penalty just before half-time.
Pity any spectators who returned to their seat late for the second half, for within three minutes of the restart the Reds had scored twice