Chelsea manager Jose Mourinho believes his team's lead at the top of the Premier League is misleading.
Chelsea are now four points clear of both Arsenal and Liverpool - who won 3-0 at Southampton - while Manchester City are six points behind, albeit with a far superior goal difference.
Mourinho said: "The gap to Man City is a fake advantage. If they win their [two] games in hand, they're top."
City do not play in the Premier League this weekend as they face Sunderland in Sunday's Capital One Cup final.
Manuel Pellegrini's side have 57 points from 26 games, while Mourinho's men have 63 from 28.
But City's goal difference is 12 better than Chelsea's, a deficit that will be hard to recover in 10 matches.
Chelsea and Fulham played out a drab first half at Craven Cottage before Andre Schurrle netted a second-half hat-trick.
And Mourinho said: "At half-time, I told them nothing - nothing - not a word. I walked in, then I walked out. I don't know if anyone else gave a team talk. I was not inside the dressing room.
"The second half was a great reaction to the worst performance of the season.
"The players knew the first half was really poor. I haven't had many first halves like this one - it was very bad.
"The second half was one of the best performances of the season. We moved the ball around well. If I could've made 11 changes, I might have done, but I could only make three - so I did nothing.
"Schurrle is still in a learning process about the Premier League. You play aggressive teams and players - but he is cold in front of goal."
Fulham, meanwhile, remain deep in relegation trouble, are winless in eight league games and are five points from safety
Their manager Felix Magath admitted: "Chelsea were too good for us. They played very well, wanted to win and were the better team. There were some good situations for us in the first half but we are responsible for not playing so well.
"We will not stay up with this kind of defending and need to learn better. The biggest problem was that our captain [Brede Hangeland] was gone after a few minutes [after a nasty clash of heads with team-mate Kieran Richardson]. If he could have played the whole game, we could have had a different result.
"You cannot ask for a win against the Premier League leaders, so the next games are the ones we will be looking to win."