LONDON - For a team at the top of the Premier League and with a defense more than twice as effective as its nearest rival, Chelsea is in great need of a victory over Arsenal on Sunday.

The onus would appear to be on the Gunners, since they need to trim a 10-point deficit on the leaders, but Chelsea is in the midst of a poor run of results and is facing its first real test under coach Luiz Felipe Scolari.

Chelsea has won just two of six last matches, been knocked out of the League Cup and stuttered badly in the Champions League.

Having taken just one point from home matches against Manchester United and Liverpool, the Blues need a win to boost morale.

"It's a huge game," Frank Lampard said. "They're going to want to stay in the title race; we need to try and get a win to try and stay at the top of the table. It's a chance for us to put more distance between us and them."

The Blues still lead the standings on goal difference over Liverpool, but appear uncharacteristically vulnerable. Nicolas Anelka is still on top form, taking his season tally to 14 on Wednesday and replacing Didier Drogba as main striker.

Meanwhile, Arsenal's form has been so poor and Arsene Wenger's judgment has been questioned over his choice of William Gallas as captain. The club's most successful manager was forced to strip Gallas of the title last week, handing the duty to Cesc Fabregas, when the defender criticized his teammates publicly.