The Blues restored their three-point lead over United with a 2-1 win against Portsmouth last night, their first victory in three games.

United boss Sir Alex Ferguson believes his side will emerge triumphant in the title race because they are traditionally stronger after Christmas but Lampard disagrees.

"United have a history of doing it but we've had a history of doing it as well," declared the midfielder. "We're very determined.

"We had a really bad time around this time last year but when Guus Hiddink came in we were in the best form by far of anyone in the league. We can do that again."

Chelsea now face Lampard's former club West Ham on Sunday and he is convinced ex-Blues duo Gianfranco Zola and Steve Clarke can save the Hammers from the drop.

Lampard has been jeered by West Ham fans every time he has returned to Upton Park following his £11million move to Chelsea in 2001.

But he is not gloating about their plight near the foot of the table.

"It's difficult for West Ham at the moment," he said. "They have a lot of financial difficulties and have had to sell a lot of players.

"I have a lot of respect for Gianfranco and Clarkey and I don't want to see them do badly at all. They're great lads. It's difficult but then it's a difficult league."

Hammers midfielder Jack Collison, meanwhile, insists keeper Robert Green can bounce back from his blunder against Bolton.

The England number one dropped what should have been a simple catch at the feet of Ivan Klasnic, who promptly put the Trotters on their way to a 3-1 victory.

Collison said: "It was a bit unfortunate and Greeny has been magnificent for us. I am sure he is going to bounce back - and what better match than to do it against Chelsea."

United take on Fulham at Craven Cottage on Saturday with Ferguson pleased his side appear to have answered his call to be more clinical.

"Our scoring rate last season was good enough to win the title but it hardly blew anyone out of the water," said the Scot.

"A few weeks ago I asked the players to be more decisive with their chances, especially in the early part of a match. It seems they took my plea on board."

United got back to winning ways after their defeat by Aston Villa last weekend with a 3-0 victory over Wolves on Tuesday, but the main talking point proved to be Mick McCarthy's team selection.

The Wolves boss chose to rest all 10 of the outfield players who starred in their 1-0 win at Tottenham, with the key clash against Burnley on Sunday uppermost in his mind.

The tactics have been widely condemned and the Premier League have asked McCarthy to explain his decision, but chief executive Jez Moxey believes his man knows best.

"He's done it once, he might do it again," said Moxey. "Mick McCarthy is his own man. It's not for me to try and influence what he thinks is the right team to win a game."

Burnley go into the Molineux match fresh from a 1-1 draw with Arsenal, who will look to get back to winning ways against Hull on Saturday.

Aston Villa, who are level on points with the Gunners after successive wins over Manchester United and Sunderland, host Stoke this weekend while fifth-placed Tottenham travel to Blackburn.

Manchester City boss Mark Hughes has had a difficult week, with the news Joleon Lescott will be out for up to two months after knee surgery followed by yesterday's 3-0 defeat at Spurs, and he will hope for better against faltering Sunderland.

In other games, Liverpool travel to bottom side Portsmouth and Everton meet in-form Birmingham on Sunday.