England head coach Steve McNamara admitted Saturday's tough test against Fiji was much-needed ahead of the World Cup quarter-finals.
England trailed 6-0 just before half-time but roared back to clinch the runners-up spot in Group A with a 34-12 victory over Fiji at Hull's KC Stadium.
Tougher challenges await in the knockout stages, notably a potential semi-final in two weeks' time against holders New Zealand.
"It was a proper Test match," McNamara said. "We always knew it would be.
"It was a very tough test match. It's exactly the test we needed. I think it bodes well for us in the quarter-finals."
England comprehensively beat Fiji thanks to a scintillating start to the second half as they scored five tries in 15 minutes after the break.
McNamara added: "We were a little bit more direct (in the second half) and I think we did that tremendously well."
Prop Sam Burgess added: "We did not play to our strengths in the first half. It was a great team effort (in the second half) and I'm very happy for the team."