London, Dec 17 (DPA) Chelsea and Manchester United will be wary of slip-ups this weekend as the two continue to battle it out for supremacy at the top of the English Premier League.

Both teams dropped points last weekend but rebounded in midweek and will be looking for maximum points again, but both have testing encounters.

Chelsea, three points clear of United at the top, are away to London rivals West Ham United, a side struggling in the bottom three and desperate for points.

Champions United are away to Fulham, a side buoyed by reaching the Europa League knockout stages and who won the corresponding fixture last year.

Chelsea ended a run of four games without a win by edging out bottom side Portsmouth in midweek and captain John Terry said they are back on track in the title race.

“I understand everyone feeling frustrated, our defending of set-plays was unacceptable (against Portsmouth),” he said. “(But) we’re still on target for 90 points this season and we are the only club which is.

“Saturday was the first time we have dropped points at home this term and I want it to be the last.”

Frank Lampard, whose penalty secured the win over Portsmouth, said confidence was not quite 100 percent within the team at the moment.

“We’re having a patch at the moment where we’re not pulling away from teams when we might do and every free kick and corner seems to drop to them in a funny way,” he said.

“We are being punished every time and it is just a phase we’re in. We’re going 1-0 up and then not pushing on like we were a few games ago. It’s a problem at the moment.”

West Ham lie second-from-bottom in the league, with concerns about the ownership of the club perhaps affecting their performances on the pitch.

But while the visit of Chelsea would seem to be the last thing a struggling side would want, West Ham assistant manager Steve Clarke said the opposite could be true.

“Chelsea is a good game for us, one we should look forward to,” he said.

“We know the crowd will get behind us, like they always do. They understand the situation, they know we are working as hard as we can and they will get behind us. Hopefully it can be a good weekend.”

Behind the front two, third-placed Arsenal have to bounce back from a disappointing draw against Burnley in midweek by beating Hull City at the Emirates.

But they will have to do it without their captain Cesc Fabregas, who picked up an injury in midweek, adding to their injury worries, with Robin van Persie a long-term absentee in attack.

Aston Villa, level on points with Arsenal, will hope to continue their surge up the table by seeing off Stoke City, while fifth-placed Tottenham Hotspur go to Blackburn Rovers.

Liverpool, chasing that fourth spot and a Champions League berth, will be out to build on their return to winning ways by taking all three points at Portsmouth.

Birmingham City try to make it six wins in a row by claiming victory at Everton, while Manchester City host Sunderland, Wolves clash with Burnley and Wigan Athletic entertain Bolton Wanderers in the weekend’s other matches.