Chelsea drew 1-1 draw at home to Aston Villa on Tuesday (NZ time) as Oliver Giroud's first-half header was cancelled out shortly after the break by Anwar El Ghazi.
Lampard made six changes to the team that began Saturday's 3-1 defeat to their London neighbours Arsenal, and his gamble on Giroud paid off when the French striker stooped to head in a cross by Ben Chilwell in the 34th minute.
It was Giroud's third goal in four league starts this season, a contrast to a poor run for Timo Werner who has failed to score in the league since November 7.
The German, signed from RB Leipzig in the summer, appeared only as a substitute.
Villa drew level in the 50th minute when El Ghazi sidefooted a volley at the far post through the legs of Chelsea goalkeeper Edouard Mendy after a cross by Matty Cash.
Chelsea protested in vain that their defender Andreas Christensen had been fouled in the build-up by Jack Grealish.
The result means Villa and Chelsea sit in fifth and sixth place in the table respectively.
Leicester drop points at Palace
Leicester City moved up to second after a 1-1 draw at Crystal Palace when Harvey Barnes cancelled a Wilfried Zaha goal at Selhurst Park.
Leicester will remain second overnight with Everton, level on points with them, after their home match against Manchester City was postponed following more positive COVID-19 cases at City.
Leicester dominated the bulk of the game, but failed to take their chances and missed a first-half penalty while striker Jamie Vardy only came on as a second-half substitute.
"We're disappointed not to get three points and we weren't as clinical as we have been, but it's onto the next game," Barnes said.
"It has been a very busy schedule with some great results so we're happy with where we are in the table."
Leicester could have taken an early lead after Luke Thomas was fouled in the box by James Tomkins, but Kelechi Iheanacho's weak effort from the spot after a stuttering run-up was swatted away by goalkeeper Vicente Guaita.
"Guaita is a good keeper, he's been brilliant ever since he came here and he saved me today. Hopefully, I can repay him one day," a relieved Tomkins said.
Palace made it 1-0 just before the hour mark when Andros Townsend floated a cross to the far post for Zaha to volley home from an acute angle.
However, Barnes equalised when he scored his second goal in as many games, driving a low effort from the edge of the box past the outstretched arm of Guaita in the 83rd minute.
Palace's winless run in the league has now extended to five games but Zaha was glad to take a point.
"We'll take a point today, the last few games have been hard on us," Zaha said after scoring his eighth league goal this season.
"The way we worked today I'm definitely happy and we'll take that going into the new year."