Young struck 107 and Latham smashed an unbeaten 118 to help the Black Caps overcome a sluggish start and post a commanding 320-5 after being put into bat at the National Stadium in Karachi on Wednesday (local time).
Glenn Phillips chipped in with a brisk 61 as New Zealand passed the 300-mark, which had looked like a distant dream after their wobbly start.
Pakistan were all out for 260 in 47.2 overs with Babar Azam (64) and Khushdil Shah (69) scoring half-centuries but the hosts never looked in the hunt in the Group A competition.
"I think Pakistan bowled pretty well... but the way Young and Tommy were able to rotate (strike) and get the odd boundary, that partnership set us a very good platform," New Zealand captain Mitchell Santner said.
Santer admitted even he did not expect a 300-plus score after their sluggish start and praised Phillips' breezy 61 off 39 balls down the order.
"We were thinking 260-280, but it shows what you can do if you have a platform and wickets in hand," Santner, in his first global tournament as New Zealand captain, said.
"After the score we got, the first 10 overs with the ball were outstanding, the way our new-ball guys were able to smash a length."
The hosts began well, conceding 39 runs in the first seven overs before Rizwan introduced spin and fast bowler Naseem Shah opted for a change of ends which immediately paid off.
Spinner Abrar Ahmed struck in his second over when he pegged back opener Devon Conway's off-stump with a turning delivery.
In the next over, Naseem had Kane Williamson caught behind for one and Daryl Mitchell's innings was cut short by seamer Haris Rauf.
Young combined with Latham in a century stand to set the stage for a late acceleration. The opener took a single off Abrar to bring up his hundred but fell to Naseem after a stellar knock that included 12 fours and a six.
Phillips counter-attacked in spectacular fashion in a 39-ball cameo that included four sixes.
Player of the match Latham featured in a second century stand with Phillips as New Zealand plundered 113 runs from their final 10 overs.
Saud Shakeel, partnering Babar, could not justify his promotion and fell to Will O'Rourke (3-47) and Phillips took a stunning catch at backward point to remove Rizwan for three.
Fakhar came in at number four and made 24 before losing his middle stump to Michael Bracewell.
With Pakistan reeling on 83-3 at the halfway stage, the onus was on Babar to keep the hosts in the game and Salman Agha (42) played some lusty shots to cheer the crowd.
Babar hit Santner (3-66) for a six but fell to the spinner in the 34th over after which the crowd started leaving the stadium.
Khushdil hit 10 fours and a six in his 49-ball blitz but New Zealand ran out comfortable winners.
Death bowling and injury
Rizwan said wayward bowling in the death overs and Zaman's injury robbed them of momentum.
"We didn't expect they would get 320. We thought they'd get around 260 when we took those early wickets," he said at the presentation ceremony.
"The Will Young-Latham partnership was crucial. We tried, but they played very smartly and that's why they got to that total. We lost momentum twice, first in the death overs and then in the powerplay with the bat.
"That was the time to gain momentum in a 320-plus chase. Having Fakhar Zaman (as opener) was crucial. You know how he bats in the powerplay."
Pakistan will fly to Dubai where they face arch-rivals India in a must-win match on Sunday (local time).
New Zealand face Bangladesh in their next match on Monday.
