Manchester United 3 Portsmouth 0:Alex Ferguson got the 20th anniversary present he was looking for at Old Trafford as Manchester United ripped Portsmouth to shreds and opened up a three-point lead over Chelsea at the Premiership summit.

Despite his vast achievements during two trophy-ladened decades at United, Ferguson prefers to look forward rather than back and has his sights trained on lifting a ninth league title next May.

Although the durability of his squad may still be questioned, there are no quibbles about the quality of their play at the moment and, after shattering Bolton last week, United laid waste to another early-season high-flyer.

Two goals up after 10 minutes courtesy of a Louis Saha penalty and Cristiano Ronaldo's blistering free-kick, the Red Devils pounded the Pompey area throughout and only the heroics of keeper David James kept the score down.

Even James could do little about Nemanja Vidic's first United goal as the Serbian rose to meet Gary Neville's cross and power home his side's third midway through the second half.

Ferguson was afforded a spontaneous standing ovation by the home fans towards the end but there was no big fanfare for him before the game, just his usual sprightly walk down the touchline.

But if the United board, and presumably Ferguson himself, had decided to keep the afternoon low key, it quickly became apparent the Scot's players had something special planned.

Having described last week's thunderous opening at Bolton as the best performance from his team in three or four years, Ferguson could hardly have expected a repeat performance so quickly.

The hosts were aided in their quest by the absence of Sol Campbell from the Portsmouth starting line-up, the former England defender sent home from the team hotel last night after picking up a stomach bug.

Campbell has been one of the mainstays of Portsmouth's impressive start to the season and his experience was badly missed as the visitors defence found themselves ripped apart constantly from the very first minute.

There was certainly some sleeping going on in the Pompey rearguard when Neville took a quick throw, releasing Wayne Rooney who had burst into the box totally unmarked.

Dejan Stefanovic's desperate attempts to recover his ground only resulted in him clipping Rooney from behind with sufficient force to warrant a penalty award from referee Mike Dean.

It was United's first spot-kick of the season and Saha wasted little time in belting home his seventh goal of an impressive campaign.

Saha was also heavily involved in the Red Devils second in the sense he was the man clattered by Campbell's replacement Andy O'Brien to provide Ronaldo with his free-kick opportunity.

The Portugal winger is making a habit of causing panic with such chances and James had no chance of keeping out the fizzing shot which flew over the wall and dipped into the bottom corner.

Just as Jussi Jaaskelainen's was Bolton's hero seven days ago, so Portsmouth were equally heavily reliant on their keeper.

As a former Liverpool and Manchester City man, James is hardly likely to receive a warm reception from the Old Trafford faithful.

Yet there must have been some grudging admiration for the former England man as he pulled off a string of fine saves to keep the hosts at bay.

Old international team-mates Neville and Rio Ferdinand were among those denied, as was Rooney when the youngster burst into the box.

On that occasion, James pushed the ball straight into the path of Paul Scholes, whose instant shot was headed off the line by O'Brien.

James' heroics continued after the break too, with Vidic and Neville denied before a third United goal finally arrived.

By then though, Portsmouth could somewhat amazingly have been level. Matthew Taylor forced an excellent reaction save out of Edwin van der Sar just before the interval, then Nico Kranjcar thrashed wildly at the ball with the goal at his mercy on the hour mark.

Had Pompey got anywhere near parity, it would have been a total injustice and any lingering hopes of a comeback were extinguished when Vidic rose to power home Neville's cross.

It could, and probably should, have been more. Saha was once more denied by James before the Frenchman lashed a late shot into the side-netting. Ferguson, perfectionist that he is, would no doubt have had a little grumble at that.