It was the 34-year-old England international's fourth strike in as many league games and he is inching closer to Bobby Tambling's all-time Chelsea record of 202 goals.
The Londoners had gone four games in all competitions without a win but interim manager Rafa Benitez believes results will improve now his squad is getting back to full strength.
"It's important to have more bodies because you can change players for others with fresh legs. With the quality we have it will make things easier," Benitez told reporters after his side stayed third, 13 points adrift of leaders Manchester United.
"Oscar had a bit of cramp today and Gary Cahill did as well because they are playing so many games and they were also away on international break in midweek," added Benitez, referring to two players he was forced to take off in the second half.
"We were able to move David Luiz from midfield to centre-back and we didn't have that option before. Juan Mata was on the bench and we were able to bring him on for Oscar so that was really good too.
"I was also able to bring on Yossi Benayoun and Marin so it's much better now that we are able to manage the game in a different way. In the past it was more difficult to change the game," said Benitez.
Benitez's side have squandered several leads in recent matches and the Stamford Bridge faithful started to get jittery before Lampard fired a low shot home with three minutes to go.
