The Blues completed a comeback in front of their home fans at Stamford Brigde to go atop the Premier League table.
Former Blue Patrick Bamford gave the visitors a surprise lead inside the opening four minutes, but in-form Olivier Giroud pulled parity for the hosts after meeting a Reece James cross inside 27 minutes.
Both teams had the opportunity to take the lead before halftime but could not convert their chances.
Chelsea took the lead inside 61 minutes when Kurt Zouma rose highest to meet a corner from Mason Mount.
Leeds kept knocking on the door for an equalizer during the dying embers of the game, but a blistering counter attack from Lampard’s men saw them double their advantage through substitute Christian Pulisic and that was enough to give Chelsea their sixth win of the league season.
“We started brilliantly in the first few minutes but then they scored so that's a test straight away. We created so many opportunities, stayed positive and defended well,” the Englishman said after the game.
“We had to accept they would probably create chances but I thought we dominated the game in terms of action in the two boxes. I thought we deserved the win though it was a bit nervy until the end.
"It's our job to get the message across. Even our centre-backs, Thiago Silva, the moments he had to bring his quality through, he did that. There were lots of good individual performances."
Lampard was further asked if Chelsea could mount a title challenge.
"It's early December and there's a long way to go. But we are a progression. When you bring in new players, have young players and you're trying to integrate... Whether it's this season we get to the heights we want, I don't know. But we are moving in the right direction. I'm really pleased. It's work on the training ground and staff behind the scenes. At our level, at Chelsea, people will always question us. Our job is to not get caught up in the chat. We have to keep our feet on the ground. There's a long, long way to go. At the minute we're in a patch."
