It was Chelsea’s seventh consecutive away win, equalling a club record which has stood since 1989.
The visitors created a huge number of chances at Vicarage Road but failed to put the game out of reach and survived a late scare as Kepa flew to his left to keep out goalkeeping counterpart Ben Foster’s last gasp header – who also produced a string of remarkable saves to keep Chelsea at bay.
An early Tammy Abraham goal following a sublime Jorginho pass and Christian Pulisic’s second half tap in won it for the Blues, who came under late pressure after they gave away a penalty which was converted by Gerard Deulofeu.
Lampard was impressed by the team performance, but picked out Kepa for special praise.
He said: “It was a brilliant save, we got what we deserved. I am pleased and it’s great for his confidence.”
The Chelsea manager admitted to being nervy at the end of the game but insisted they were well worth the three points.
“We dominated the game, played some great football,” He added.
“We created enough chances. Should have been three or four goals. Credit to Ben Foster. A bit of a story of our season.”