The Blues raced into a 1-0 lead through Mason Mount, who capitalised on Wilfred Ndidi’s mistake before driving home.
But the Nigerian headed the equaliser to make amends with the visitors missing a host of chances late on to take all three points.
“Really good start, fantastic start, could have been two or three goals up and quick, bright, energy in the team,” Lampard said on reflection.
“After that, we allowed Leicester to get back into the game, struggled to keep the ball ourselves as well as we should have done, as well as we had been doing and then second half, I wasn’t very happy.
“We offered them too many chances to counter-attack, we didn’t have enough calmness on the ball to keep the ball and move it and switch the play and by doing that, we allowed them right back into the game.”
Lampard also enjoyed his reception from the home fans upon his return but is aware he needs a win soon after starting with three games without a victory.
“It felt great,” Lampard said. “It’s a special moment for me to come back here and manage the club. My focus was on the game and trying to win.
“It’s a results business. The performance against Manchester United made be happier overall compared to today.
“We have to have game management. That’s something for all of us to work on.”