The Welsh XV had plenty of possession to win the game but did not break the gainline often enough up front or run strongly and directly enough behind.
The Welsh forwards more than held their own but behind the scrum it was the tourists who had the edge in both pace and penetration.
Two of the threequarter line, centre Luke McAlister and wing Joe Rokocoko, played in the under-19 side that won the Junior World Cup in Chile last year and they looked the class players of the night.
Rokocoko made the first try with a powerful blindside surge and well-timed pass to supporting scrum-half Scott Cowan to give New Zealand a 7-6 lead, McAlister kicking the conversion.
Cardiff fly-half Nick MacLeod had kicked two penalties to give Wales a 6-0 lead and his third just before half-time put Wales into a tenuous 9-7 lead at the interval.
McAlister kicked New Zealand back into the lead with a penalty before replacement wing Tony Koonwaiyou dramatically snatched the ball out of the grasp of Llanelli full-back Ceiron Thomas to sprint clear for a try converted by McAlister.
Wales threatened but handled sloppily in the face of aggressive defence. The forwards with hooker Huw Bennett (Swansea) and No 8 James Malpas (Cardiff) continued to make a real game of it.
Wales: Pens - N MacLeod (3). New Zealand: Tries - S Cowan, T Koonwaiyou; cons - L McAlister (2); pen - McAlister.
New Zealand Schools will face Welsh Schools U18 at Neath RFC on Friday 18 January. The match kicks off at 7.15pm
Head coach Rowland Phillips and key front rower Carys Phillips look ahead to games against Spain and Ireland as Wales Women ramp up their preparations for the forthcoming Six Nations. The two warm-up games are a 'massive opportunity to refine the squad' according to the Welsh camp.
Martyn Phillips has discussed details of the newly published 'Strategy for Welsh Rugby' which puts in black and white terms the plans and direction of the governing body of the national sport in Wales for the next decade.
WRU chief executive Martyn Phillips has urged Welsh rugby fans to follow in the footsteps of their soccer counterparts at last summer's Euro Championship by backing their team to the hilt in the upcoming RBS 6 Nations campaign.
Chief executive Martyn Phillips has highlighted the plans for Wales to become a breeding ground for national and elite club rugby coaches, which are contained in the WRU's 10-year 'Strategy for Welsh Rugby'.
Andrew Coombs is enjoying his new role as Nelson forwards coach. The former Dragons and Wales lock has big ambitions to become a professional coach but feels it's important to learn the ropes in grassroots rugby and where better than his home club Nelson, with friends and family close to hand.
Students at Brynllywarch Hall School, near Newtown, have transformed their own lives, and are now having a positive impact on others through rugby. The sport has had a life-changing effect on the well-being of the students who are now delivering rugby sessions to local primary schools and playing for a new mixed ability side
Wales reached their first semi-final since 2013 in the opening round of this season's HSBC World Rugby Sevens Series in Dubai. WRU TV's Graeme Gillespie recaps on what proved to be an eventful tournament
Wales and Ospreys back row James King, who came through the North Wales age grade system, nominated North Wales Regional Community Rugby Manager Marc Roberts, in the WRU's 'Diolch' initiative where squad players thanked those who played a part in their rise to the top.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.