In Hastings, Georgia Hulls combined with Brooke Somerfield to win in 23.64 seconds only two-hundredths of a second ahead of Zoe Hobbs and Jade Sutherland Smith with Lucy Sheat and Olivia Eaton close behind.
It was even closer in Whanganui with three teams finishing within hundredths of a second - bringing perhaps the biggest roar from the crowd.
Zoe Hobbs combined with Georgia Hulls (23.53) with Brooke Somerfield and Lucy Sheat and Briana Stephenson pairing with Olivia Eaton unable to be separated on 23.57 seconds.
The relay group had been together all week with national coach Kerry Hill staying along with the young athletes on the Classic Tour at Wanganui Collegiate.
The training time and the opportunity to combine in the 2x 100m events in both Hastings and Whanganui brought its reward when they combined as 4 x 100m teams in the final Classic in Wellington on Friday.
The team of Brooke Somerfield, Lucy Sheat, Zoe Hobbs and Georgia Hulls combined to stop the clock at 45.04 - well under the world qualifying performance of 46.00 and also inside the existing New Zealand under-20 record of 45.57.
What is especially pleasing is that the B-team ran in 46.60 which means the team travelling to Poland in July can take quality additional runners.
I am excited we have a quality junior team but just a little sad the almost 22-year-old national record has finally gone.
The record had been set by a great group of young women at the World Junior Championships in Lisbon in July 1994, where they finished a very creditable sixth.
The quartet of Kelly Miller, Jeanette Wise, Caro Hunt and Jane Arnott were part of the first major national team I travelled with as team manager. Miller was a Whanganui sprinter of real quality.
The fact that that team placed so highly should greatly encourage the present squad who are already half a second faster with six months to go at an age when improvement can be considerable.
Local sprinters performed well at the Capital Classic.
Harry Symes, an hour after acting as pacemaker in the 800m, won his grade of the 400m in a respectable 50.69 in breezy conditions.
Olivia Seymour, a member of the Wanganui Collegiate School winning 4 x 100m junior team should be heartened by her win in her grade in a personal-best.
They, like many other athletes, will be back in action at club night at the start of the new school year next Tuesday.
A week later sees the first of two nights of the MWA Championships at Cooks Gardens with the second meeting a fortnight later in Palmerston North.
The next major event is the Porritt Classic in Hamilton on Saturday, February 13. Many will travel for the school team 1500m races and the medley relays which are part of the meet.