Wesley Fofana’s first-half try helped hand les Bleus a slender 10-9 lead at half-time after three Owen Farrell penalties kept England in touch with their bitter rivals.
And the Red Rose impressed in the second half as Manu Tuilagi scored his first try of the campaign, while Farrell and Toby Flood kicked key points to ensure Lancaster’s side got over the finishing line, with a 23-13 win.
“I’m delighted with the players,” said Lancaster.
“We kept our composure and the defence grew. We didn’t quite get the tempo that we wanted all the way through the game but our bench made the difference.
“If you said to me at the start of the day that we’d get a 10-point victory, I would have taken it.”
He added: “We showed a great level of maturity for a young side.
“We had an average age of 24 and 200-odd caps in the side, and we were playing a side which reached the World Cup final and have got lots of world-class players in their side.
“Our ability to problem solve and come out on the right side is a great quality to have.”
Lancaster also reserved special praise for his captain Chris Robshaw after the Harlequins No7 was named man-of-the-match for the second successive Six Nations game.
“He [Robshaw] was outstanding. Him and Tom Wood in the back row in the last 10 minutes were everywhere,” added Lancaster.
“Chris was outstanding with his leadership, ability to play and make the correct decisions under pressure. It’s a testament to him.”
MORE: The latest football news
MORE: The latest tennis news
BIOGRAPHY: Ethan Hazard
BIOGRAPHY: Daniel Sturridge