Lampard scored twice in the second half to break Bobby Tambling's scoring record with 203 goals for Chelsea 12 years after arriving from West Ham.
The England international dedicated the feat to his late mother who he always remembers in his goal celebrations.
"I have been here a long time, I lost my mum a few years ago and she was my biggest supporter so it's for her," Lampard told Sky Sports 2HD.
"It's right up there. Not much beats Munich [last season's Champions League success] because that was amazing for the team and the club but personally it is another great day and I am really pleased.
"Bobby Tambling is a great man and I was pleased to level, but didn't want to overcook that celebration out of respect for him.
"But then to go and break it I was delighted and I am just very pleased to do it today."
Lampard also thanked his team-mates and the Chelsea fans for helping him reach the landmark.
"It means everything, it's amazing," he said. "The support I have had from my team-mates I think you can see that there at the end and I am thankful to every one of them because they are the ones who put it on the plate for me sometimes.
"And the fans they have all been willing me to do it for a long time and have probably been frustrated alongside me not getting there.
"I am just delighted; the way the fans were there at the end is everything what it means to me."
Asked if he hoped for more special days next season with Chelsea, Lampard, who is out of contract this summer, concluded: "I hope so."