Manchester United 2 Liverpool 1  IT IS EXACTING to pursue a national prize in the midst of a domestic feud. Liverpool could scarcely have known whether they were attempting to land a blow in the fight for the last Champions League place or daze opponents aiming to retain the Premier League title. All Manchester United would have known is they were taken to the limits while seeing out a win that puts them back at the top of the table.

The stress and uncertainty was embodied in the 90th-minute incident when, after Fernando Torres had sliced his effort, the ball went to the Liverpool substitute Yossi Benayoun, who headed weakly into the hands of Edwin van der Sar.

He should instead have deprived United of two of these three points.

Alex Ferguson’s players felt the tension as they strove to call a halt the sequences of three losses against Rafael Benitez’s side.

The previous weekend, the United manager had extolled the impact of Dimitar Berbatov in the 3-0 win against Fulham. The compliments sounded even then as if they were doubling as consolations for the Bulgarian, who was indeed left on the sidelines. Ferguson would not countenance an extra centre forward beside Wayne Rooney when so much depends on midfield in these confrontations.

That outlook, in turn, opened the way for Park Ji-Sung to start. He has energy and adaptability to flesh out any plan. In the rout of Milan he had been in an advanced midfield post to hamper the work of the visitors’ playmaker Andrea Pirlo. Here his presence led to defeat for Liverpool. Park got in front of right back Glen Johnson to head in an ideal Darren Fletcher delivery after 60 minutes.

United’s relief at the outcome will be complemented by satisfaction at the sight of Ryan Giggs making his return, after an arm fracture, as a substitute. The Welshman’s experience is one United must plan to draw on heavily in the weeks ahead.

There had been scepticism over the claim by the Old Trafford manager in his programme notes that he has “a twinge” of sympathy for Benitez. Considering recent results the feeling might just as easily have been a pang of indigestion at the recollection of three consecutive defeats by Liverpool.

The United manager’s stomach would have churned once again when the visitors took the lead in the fifth minute through a goal from a forward who keeps distressing his side.

After Torres had dispossessed Michael Carrick, the visitors’ striker backheeled the ball to Steven Gerrard. The captain, from his very advanced midfield position, fed the ball to the right and Dirk Kuyt delivered a deep cross. The unmarked Torres, who had made up a great deal of ground to be in position, headed handsomely beyond Van der Sar.

The occasion had galvanised visitors who had probably forgotten their Europa League fixture last Thursday evening and showed no signs of fatigue.

All the same, United did equalise swiftly. Javier Mascherano persisted in fouling Antonio Valencia until both men were on the verge of the 18-yard line. The referee, Howard Webb, having initially played the advantage, awarded a penalty in the conviction that the visitors’ midfielder had not released his opponent before reaching the box.

Ferguson wanted a red card for the Liverpool midfielder. Mascherano may not have been the last man, but the United manager was indignant even in triumph and still argued Jamie Carragher could not have made the ground to deny Valencia a shooting opportunity. It seemed a close call, however, and Webb was probably right not to dismiss a player when there was an element of doubt. The episode continued to be highly fraught in any case.

Torres dragged his boot across the penalty spot in an attempt at distraction that did seem to have an effect.

Pepe Reina was able to dive to his left and block Rooney’s spot-kick but that parry directed the ball back into the middle of the goalmouth, where the United forward knocked in his 33rd goal of the campaign.

His contribution has been indispensable and it has helped hugely in giving United their highest tally at this juncture in a league campaign since the prolific season of 2001-02. The scoring continued here yet it has to be agreed this had been an extremely attritional fixture.

Liverpool will be indignant over the officiating, but did at least show glimpses of their fortitude and talent. For their part, United’s Nemanja Vidic completed the game without a red card, having been dismissed in each of the three previous encounters with Benitez’s men.

The victors had not come through the match unscarred, but the harm was at least superficial. This had been useful practice. There are draconian tests ahead. Chelsea are the next visitors to Old Trafford.

Guardian Service