With Tottenham held by Watford earlier in the day, Chelsea would have cemented their grip on fourth place with a win on Tyneside.
But Lampard's side were unable to muster the cutting edge required to break down stubborn Newcastle and fell to Isaac Hayden's header with just 20 seconds left in stoppage-time.
Chelsea's first defeat in four league matches leaves them five points clear of fifth-placed United and Lampard is growing tired of his team's struggles against defensive opponents.
"We know we have problems at the top of the pitch in terms of we don't get enough goals. If you don't score you are always liable for a sucker punch and they got it," Lampard said.
"If we are looking for people to bring in to the areas to win games when you are controlling it, it is scoring goals", Lampard ended.