Andre Schurrle hit a hat-trick as Chelsea defeated Fulham 3-1 yesterday.
With Arsenal losing at Stoke, the Blues moved further clear and now have a four-point advantage over the rest of the field.
Despite their improved position, Mourinho is still wary of Manchester City, who are six points behind but have two games in hand.
"We have four points more than Arsenal, the same number of matches," Blues boss Jose Mourinho said.
"If City win their two matches in hand, they're top. I'm there for now, but if City win the two matches they're top. We have four points from Arsenal and Liverpool, but not yet on City."
