Despite losing Jason Roy to the first ball of the match England passed 400 for the first time in the format as brilliant centuries from Jos Buttler and Joe Root saw the hosts finish on 408 for nine at Edgbaston.
Steven Finn and Adil Rashid then took four wickets apiece as New Zealand were bowled out for 198 in reply to leave England winners by 210 runs.
It was an incredibly turnaround from a hugely disappointing World Cup showing for England and, rather than regret what might have been previously, Morgan preferred to look ahead with optimism.
He said on Sky Sports 2: “You can look back and say what you want about the World Cup, myself I’m looking forward, and I’m really excited.
“Today encouraged me even more to look further down the line and give guys more of a chance to grow as cricketers, because the more games we can get into our youngsters, the more performances they put in, and we win games along the way, holds a lot of weight come the next World Cup.”
Morgan admitted he did not expect the new England era to get off to such a flying start, but was also keen to point out that these sorts of performances need to be much more regular than before.
He said: “I’m as surprised as anybody, I certainly know how difficult it is coming into international cricket as a youngster but given that we’ve two or three new faces in our playing XI I think the way they held themselves brilliantly.
“Joe Root was outstanding, followed by an unbelievable innings from Jos Buttler, but obviously the longevity of what we do might take a little more time because the key is consistency for us. Today is an amazing performance but the closer we can get to that every game, the better we become.”
Root’s 104 off 78 balls helped England recover from Roy’s early departure but it was Buttler and his stunning stand with Rashid that powered the home side into uncharted territory.
Buttler scored 129 off 77 deliveries and put on 177 for the seventh wicket with all-rounder Rashid, who scored 69.
Lancashire wicketkeeper-batsman Buttler was named man of the match, but he was quick to hail the contribution of Root as well, saying: “You’ve got to give a lot of credit to the way Joe Root went and played. Obviously losing a wicket first ball he’s straight in and I think the way he played gave everyone in the batting order a lot of confidence to go and follow his lead.”
Buttler added of the victory: “Really pleasing win, to win with such a margin is great and gives everyone a lot of confidence going forward.”
New Zealand captain Brendon McCullum, meanwhile, admitted he erred in sending England into bat after winning the toss, but said that should not detract from a “complete” performance from the hosts.
He said: “Special performances from Joe Root and Jos Buttler, I thought they were outstanding and to post 400 in any game is outstanding, credit to England, they blew us off the park.
“I think sometimes you’ve got to admit when you get it wrong at the toss. And the way the ball probably started holding up a little bit in the second innings probably suggested we did get it wrong.
“That was unfortunate but I still don’t think it should take away from how outstanding they were with the bat and the ball and in the field. It was a complete performance from England and we’ve got some work to do.”
With New Zealand also employing an aggressive mindset under their ultra-attacking skipper, McCullum expects spectators to be in for more treats during the rest of the five-match series.
He added: “Cricket’s a funny game, the last time we played England we were on the right side of the ledger in terms of a one-sided match, on this occasion they were simply too good for us today.
“That’s the way I think both teams will play this series. There will be some cliffhangers at some point, no doubt. I think the crowds are going to be in for some outstanding cricket over the next week and a half.”