Lampard oversaw a 2-1 win for the Blues, with Tammy Abraham and Ross Barkley finding the scoresheet before Ivan Rakitic's late consolation goal.
"I'm very happy," he said. "It's been good on pitch and off pitch. Especially today, I saw a lot of signs from the work we have done which is very good. There is more work to do but it's been a good trip.
"It is always great to come to Japan and [see] the welcome we receive. For the club that's important and it's been nice for us.
"What I've learnt about the players is they're a good strong group. They've done everything asked of them and more, so they deservedly now get a couple of days off.
"We've had two very competitive games here in humidity and difficult conditions. It's a good test for the players and the tour has helped us.
"We're in a process to be fit and ready for Manchester United, our first game. The clock runs down quickly so the players have to keep working. Collectively we have to work on elements of the team I want to implement."