They had earlier led 19-11 at halftime thanks to an opening try from Kendra Reynolds and a double from Robins-Reti, but the Blues struck twice after the break to take a 23-19 lead with 10 minutes remaining.
But Robins-Reti, a five-test Black Fern who moved south from the Hurricanes this season, was sent over in the corner, and Renee Holmes produced a brilliant conversion to give Matatū a bit more breathing room, which proved crucial when the Blues were given the chance for a shot at goal but opted to try win the game instead.
Despite facing some Blues barges, Matatū held on to book their place in the final.
The Chiefs had no such worries at the end of their clash, never trailing against the Hurricanes, who provided some fight but never looked likely to snag a victory.
Tenika Willison led the way with a 20-point haul that included two tries, the most pivotal being just before the hour.
The Hurricanes had just reduced the Chiefs’ lead to 28-21 when Willison struck to make it a two-score game, and a yellow card to Hurricanes and Black Ferns star Joanah Ngan-Woo with 12 minutes to go allowed the Chiefs to seal the deal.
Matatū 26 (Cheyelle Robins-Reti 3, Kendra Reynolds tries; Renee Holmes 3 con)
Blues 23 (Katelyn Vaha’akolo, Patricia Maliepo, Liana Mikaele-Tu’u tries; Krysten Cottrell con, 2 pens)
HT: 19-11.
Chiefs Manawa 43 (Tenika Willison 2, Carla Hohepa, Luka Connor, Kennedy Simon, Mererangi Paul tries; Willison 5 cons, Hazel Tubic pen)
Hurricanes Poua 21 (Te Kura Ngata-Aerengamate, Kaipo Olsen-Baker, Layla Sae tries; Isabella Waterman 3 cons)
HT: 21-14.