The highly-ranked John McGlashan team of last season either ended up either playing the top seed or eliminating one another.
Paddy Ou came through the qualifying rounds over the previous two days only to meet former team-mate Peter Hartono, now training in Queenstown, in the last round.
Ou won 7-6, 6-2 to advance to the main draw, but then had to play another team member and frequent training partner in Carlos Reid.
Reid won 6-4, 6-2 in windy conditions.
"Paddy was very competitive in the first set but he seemed to be more affected by the wind and was a bit off in the second,'' Reid said.
He has also enjoyed the indoor conditions with success in the past.
Reid now meets national junior representative Macsen Sisam, the fourth seed, who has played for New Zealand in world competitions since the age of 12, but who is a year or two younger than Reid.
"I am just going to play my normal aggressive game,'' Reid said.
Reid has a history of strong achievement at the nationals having come third and beaten three seeds on his way in the 16s age-group.
Mitchell Sizemore had the misfortune to meet top seed Connor Heap and was satisfied he gave a good account of himself despite losing 6-3, 6-1.
He was also very pleased with his doubles form later in the day when partnering Reid to a 6-0, 6-0 win against Josh Gwynne (Canterbury) and Bjorn Pollock (Queenstown).
The duo next meet third seeds Liam Cunliffe and Luke Taplin, from North Harbour, while Ou partners Philip Hoeper (Canterbury) against Ed Batt (Canterbury) and Hartono.
In the girls event, Emilia Price, of Queenstown, lost 6-0, 6-2 to Brooke Kenny, from North Harbour, and Rebecca Dellaway, of North Otago, went down to Aucklander Isabelle Coman 7-5, 6-4.
Price has several years left in juniors and is a good prospect in the younger age-group.
Dellaway and partner Olivia Wooldridge (Wellington) had a good doubles win over Annie Coates (Canterbury) and Elys Ventura North Harbour by 6-2 6-4, but now meet top seeds Rosie Cheng, who recently won the national open title, and Ashleigh Harvey, who has represented New Zealand at junior level.
