Tammy Abraham and Christian Pulisic scored the two goals of the Blues in the second half to the delight of more than 40,000 spectators at Stamford Bridge.
"We are maintaining the gap with Liverpool and Manchester City. we must try to narrow the gap throughout the season. We are happy with our position, "commented Lampard on 'BT Sport'.
Held in check by theAjax Amsterdam in the Champions League after a spectacular match (4-4) Tuesday, Chelsea returns with success to sign his sixth victory in Premier League rankings.
"I was a bit frustrated in the first half because I felt like we had lowered the pace. I felt that if we increased it, we could win the match, "said Lampard.
In addition to the shock at the top Liverpool-Manchester City, Sunday closing, Arsenal, fifth, makes a delicate move Saturday in the late afternoon on the pitch of the fourth, Leicester.