United have built a six-point lead over second-placed Chelsea thanks to some scintillating displays that culminated in successive four-goal victories against Watford and Tottenham last week.

With Cristiano Ronaldo and Paul Scholes in majestic form, it is the attacking side of Ferguson's team that has earned most of the plaudits this season.

But the United manager, whose side host struggling Charlton on Saturday, is convinced that the destination of the title rests on United's ability to grind out narrow wins when they are below their best.

Rio Ferdinand and Nemanja Vidic's formidable partnership at the heart of United's defence gives the team a sturdy foundation and Ferguson said: "Keeping clean sheets is the name of the game at this stage of the season.

"Rio and Vidic have formed a really good partnership and they can get better because they are young enough.

"They will be the foundation of the defence for years to come."

Ferguson will hope Tomasz Kuszczak, who deputises for Edwin van der Sar as the Dutch keeper recovers from a broken nose, doesn't destabilise that defence.

Chelsea could be without Germany midfielder Michael Ballack as they try to keep the pressure on United with a win against Middlesbrough.

Ballack suffered a thigh injury while on international duty this week and boss Jose Mourinho will give him a late fitness test.

Mourinho can at least take comfort from the return of captain John Terry, who is likely to start for the first time since December 13 after recovering from a back injury.

Liverpool's new American owners George Gillett and Tom Hicks get a chance to see what their initial 218 million pounds investment has bought as Rafa Benitez's side travel to Newcastle.

The Reds are unbeaten in six matches but will be missing the suspended Xabi Alonso as they try to capitalise on the feel-good factor generated by the American tycoons.

Jamie Carragher believes the takeover can help Liverpool close the financial gap on rivals Manchester United and he said: "All the players have been talking to each other for the last few days and we're excited this is going to move the club forward.

"We're hoping it's going to help us get to the level of United."

While the race for the title hots up, the survival battle at the other end of the table gets increasingly fraught.

Nowhere will that desperation be more evident than at Upton Park, where third bottom West Ham face rock bottom Watford. West Ham have won just once in the league since Alan Curbishley took over in December and the Hammers boss admits his side now face a decisive run of fixtures.

Curbishley said: "There are now some defining matches coming up, starting with Saturday's against Watford, followed by the trip to Charlton, and the players know that they are must-win games. They realise the seriousness of the situation."

Watford are 10 points from safety and even their relentlessly up-beat manager Adrian Boothroyd is beginning to fear the worst.

"We have got ourselves in a hole and we have got to get out of it," he said. "But if we carry on playing like we did against Bolton we will only make it deeper."

Fixtures
(1500GMT kick-off unless stated)
Saturday
Chelsea v Middlesbrough, Everton v Blackburn, Manchester United v Charlton, Newcastle v Liverpool, Portsmouth v Manchester City (1715), Reading v Aston Villa (1245), Sheffield United v Tottenham, West Ham v Watford
Sunday
Arsenal v Wigan (1600), Bolton v Fulham (1330)