The pre-season contest had appeared to be heading for a goalless draw at the Nissan Stadium, until Brazil striker Damiao headed home with just three minutes to go.
Despite the result, however, Lampard will still have taken much from his side’s run out in searing temperatures against the J-League champions, with midfielder Mason Mount once again catching the eye ahead of the new campaign.
How Lampard suffered first reverse
Lampard again opted to start with Mount – who recently signed a new five-year contract at Stamford Bridge – as part of a midfield three, and the 20-year-old impressed in a first period of few clear-cut openings.
However, it was the introduction of Ross Barkley as one of several half-time changes that gave Chelsea’s play some much-needed impetus in the second half, only for Shota Arai to thwart the visitors with a number of smart stops.
As the clock ticked down, though, the home team sensed a famous win, twice going close when first Damiao thumped the bar five minutes from time, before Willy Caballero – standing in for the ill Kepa Arrizabalaga – produced a brilliant one-handed save.
But Chelsea – who brought on Christian Pulisic for his debut midway through the second half – did not heed the warning and from the resulting corner, Damiao was left totally unmarked at the far post to head home the winner.