In a grand final re-match, NSW defeated Queensland by seven wickets with rain delays forcing a Duckworth-Lewis-Stern-decided fixture at East Albury's Alexandra Park.
"I just think we bowled and fielded probably the best we have so far, we took all our catches and I thought we were pretty clinical with the ball this morning," Metro coach Anthony Clark suggested.
Queensland was restricted to 9-173 from its 50 overs.
Angus Tolhurst top-scored with 43, while No. 7 Alex Procopis contributed a patient 42 from 90 deliveries as last season's runner-up looked to post a competitive total.
Tom Straker, who shared the new ball, finished with 3-28 from 10 overs.
Metro's innings was scheduled to start at 3.15pm, but light rain meant play was delayed for 85 minutes.
The revised target was 159 from 41 overs with Riley Kingsell and Sam Konstas setting up the win with a 67-run stand from only 11.2 overs.
Konstas showed his class when he hit opening bowler Callum Vidler, who was clocked at a sizzling 143kmh earlier in the tournament, for a delightful lofted straight drive for four and then produced the shot of the innings with a flat-bat six over mid-wicket.
Another rain delay forced the players off for 18 minutes at 5.57pm, further reducing the target to 145 from 36 overs.
Twenty overs had to be bowled to complete the match and players were again forced off after 22 overs.
After a nine-minute delay, play resumed for the final time and with a target of 138, Ryan Hicks squirted the ball to the boundary at 6.58pm.
Konstas, who made his Sheffield Shield debut last week, was unbeaten on 63 from 69 deliveries.
"We were hunting as a pack, bowled well, set the tone up front and took all our catches, then polished it off with the bat," he said.
A strong crowd watched the final moments as other teams involved in the week-long carnival arrived at the ground once their matches were completed.
"It's been really good to come to Albury for the first time for the under-age national championships," tournament director Shihub Rahman praised.
"What's really good about Cricket Albury-Wodonga is it's a very strong association and a lot of credit must go to Michael Erdeljac (CAW chairperson) for his hard work and it's a credit to the relationship he has with the community."
Rahman praised all the facilities, but made special mention of the country round, which included matches at Bethanga and Yackandandah.
Tasmania's Aidan O'Connor was named player of the carnival.
The Australian team for next month's Under 19 World Cup in South Africa is expected to be named on Friday.