Blues supporters displayed a huge banner with Lampard as the focal point thanking him for his time at the club.
And Antonio Conte’s men went on to record their ninth straight victory in the Premier League.
That leaves them three points clear of Arsenal at the top of the table.
“Great to be home. Typical class from the Chelsea fans”
Chelsea hero Frank Lampard
He posted on Instagram: “Great to be home. Typical class from the @chelseafc fans.
“Thanks to everyone who helped make it happen. #bestfans #chelsea.”
Chelsea had to wait 76 minutes for the breakthrough against the Baggies when Diego Costa pounced on a Gareth McAuley error.
It was the Spaniard’s 12th Premier League goal of the season putting him one ahead of Alexis Sanchez in the race for the Golden Boot.
Chelsea will look to keep their incredible form going when they travel to Sunderland on Wednesday evening.