The likes of Christian Wade, Marland Yarde and Matt Kvesic were given a chance to shine, and the former two were among the try-scorers.
Fly-half Freddie Burns excelled with a try of his own among 20 individual points, while Kyle Eastmond joined Wade and Yarde in scoring debut tries, and Billy Twelvetrees completed the scoring.
"I'm delighted with the win," said Lancaster. "I'm pleased with the accuracy we showed against a pretty competitive Barbarians team.
"I felt at 16-0 up that we controlled the first half and I knew if we upped the tempo in the second half we could run away with it, which we did.
"Our big ball carriers did what they should, and the defence was disciplined - it gives us a good foundation to build on.
"I was disappointed to concede at the end, but overall it was a good win."