An own goal from Federico Fernandez and a second-half strike from Tammy Abraham gave the Blues a 2-0 win over the Magpies at St James’ Park.
The three points carried the Blues ahead of Leicester at the top of the league on goal difference, though Chelsea have now played at least one additional game in comparison to their rivals.
The win could have been more emphatic as the visitors missed a host of opportunities and Lampard was not prepared to get carried away with the outcome of the match.
“It’s pleasing but I’m not going to get excited about going top of the table for five minutes. It’s time to stay humble when you go top and know that it’s a long race,” he told BT Sport, content with the way the players returned after the international break.
“We played well. The result is key in these games. The Premier League is tough and relentless. You have to slap yourself. I felt they dealt with the challenge of the game today very well today.”
Lampard wants his side to develop a greater killer instinct.
“The first 20 minutes we were great because we had control and we had penetration,” he said. “Sometimes there’s a danger that that type of control because comfort, which is dangerous. We then turned it over a couple of times.
“Newcastle came out more positively in the second half. I always felt the most dangerous moment for us was on transition. Timo Werner showed that in the first half and he showed that for Tammy’s goal.
“Getting comfortable can be human nature. If we want to get to where we want to be, you don’t get complacent. We had to keep making those more dangerous passes.”
Chelsea visit Rennes on Tuesday on Champions League business.