Benitez's men are above Manchester United on goal difference following the 3-0 win at Upton Park, courtesy of two goals from Steven Gerrard and a late Ryan Babel strike.

The focus is now on how United, with two games in hand, get on against their neighbours.

"We have done our job," Benitez said. "We have to keep winning, that's all we can do. We needed to get three points and put them under pressure, and now we will be cheering and supporting Manchester City.

"It's a derby and if they make a mistake they will be feeling the pressure. Manchester City are a difficult team to play against."

Fernando Torres returned to Benitez's starting line-up after a hamstring injury and took 76 seconds to make an impact, sending Gerrard through to round Robert Green for the opener.

"If you have Torres and Gerrard on the pitch, it's a massive difference," Benitez said.

"The other team are always thinking 'who will score - Gerrard or Torres?'. It's more difficult for them."

Gerrard's second came seven minutes before the break after Torres was hauled down by Luis Boa Morte, who was furious at being denied a free-kick just before conceding the penalty.

Gerrard's penalty was saved but he tucked home the rebound.

"We're happy with the result, happy with the clean sheet. We've put a little bit more pressure on United," Gerrard told Setanta Sports 1.

"If they win their games, fair play to them, they deserve it, but we've got to keep the pressure on.

"City have just come into a bit of form and derby matches are never easy. We wait and we hope that City can do us a favour - but the important thing is that we do our job.

"It'd be nice to still have it in our hands but we've got ourselves to blame by not winning football matches we should win."

Liverpool have only lost two games this season so it is likely that they finish runners-up despite United being beaten more times.

"I don't remember (if this has happened before), but we are doing a good job, losing just two games," Benitez said.

"I was talking to some people the other day and if you analyse the two games we lost - against Middlesbrough for the first 30 minutes we were on top, and against Tottenham it was one of our best away performances of the season. It's unbelievable, but that's football."

It could have been different for West Ham if David di Michele kept his composure when racing through on goal just before the break.

He lost his footing as Jose Reina approached - and to rub salt in the wound he got booked for diving.

"I don't think he looked for it," said Hammers boss Gianfranco Zola. "The referee booked him, but he just lost his legs and lost his balance.

"I don't think it was a simulation. What can i say, Di Michele doesn't get many goals, but he is a key player for us."

Zola admits there is a gap between the top four and rest but his job is to close the gulf.

"I don't think on the pitch there was a big difference," he said. "In the first half we probably played better than them, the quality of the passing was good."