Ruud van Nistelrooy scored the only goal as Manchester United continued their assured start to the season. Thomas Sorensen made a brilliant save to deflect a shot from Park Ji-Sung against the crossbar, while a Wayne Rooney volley was cleared off the line. Park missed a good chance after exchanging passes with Rooney before Sorensen saved headers from both Gabriel Heinze and Cristiano Ronaldo. But Van Nistelrooy eventually scored, tapping home from Ronaldo’s cross. It means United have now won their opening two Premiership games as they seek to win back the Premiership title after two barren years. Sorensen was in brilliant form for Villa but he was eventually beaten as David O’Leary’s awful record at Old Trafford continued. The Irishman has yet to register a win at United in 14 attempts as a manager. The match started promisingly for Villa and the first half hour was much as O’Leary would have wanted - a low key affair, illuminated only by the energy and industry of Park. United pressed and probed for chinks in the Villa defence, which held firm despite the early loss of Jlloyd Samuel through injury. Park cut inside after 28 minutes and unleashed a thunderous right-footed strike that Sorensen did superbly to tip on to the crossbar. Minutes later Rooney adjusted his body shape and volleyed goalwards direct from corner but Peter Whittingham cleared. Sir Alex Ferguson had opted to select the same team that defeated Everton last Saturday, starting with Park and Darren Fletcher out wide and Ronaldo on the bench. As a consequence United struggled to get behind the Villa defence and the visitor’s restricted the home team to long-range efforts, though Scholes went close with a curling 25-yard strike on the stroke of half time. United enjoyed more success after the break. Minutes into the second half a delightful one-two between Park and Rooney opened up the Villa defence, though the Korean dragged his shot wide from a good position. Park was replaced by Ronaldo - and John O’Shea with Gabriel Heinze - just before the hour mark. And both replacements came close to scoring headed goals within minutes of their introduction - Heinze with a solid contact from a free-kick and Ronaldo from a cross headed across goal. Both, however, failed to find a way past Sorensen. The pressure eventually told when Olof Mellberg attempted to head Ronaldo’s cross clear but only succeeded in directing it goalwards and Van Nistelrooy tapped home from a yard. The outstanding Sorensen kept his team in the match with a point-blank save from a Scholes header. Sorensen saved again from Scholes close to full-time but, apart from a corner that he easily collected, United keeper Edwin van der Sar had little to do at the other end of the pitch *Aston Villa manager David O’Leary:* “We defended really well until Olof Mellberg made a mistake and we gave a stupid ball away. “I am an attack-minded coach and like to take people on but circumstances dictated my plans because we had a few players injured. “Everyone is working to bring players in. Within the budget we are trying to do that but we have to get on with it. That’s life. The only worry I have is we will lose players through injury.”