"Mahinarangi Millar-Potaka had an outstanding defensive first half, linking well with Kahureremoa Aki and Waimanawa Potaka-Osborne-Whanarere to apply pressure to Mere Te Aroha's midcourt," Peina said.
Javell Pereka and Taliatua Leo once again put in a good performance, while the injection of Ahungarangi Whanarere at half time added defensive pressure.
"Ina Whanarere-Nahona and Sharnarose Pehi worked the shooting circle really well, splitting the defence and giving our attacking midcourt combination, Kahureremoa Aki and Waimanawa Potaka-Osborne-Whanarere, great safe options."
Captain Kahureremoa Aki lead the team, creating turnover balls and being available to assist with bringing the ball through court.
"We are extremely proud with the team's win last night, it was always going to be a great battle against Mere Te Aroha who have played outstanding all season. Next week will be our club's first premier netball final appearance since 2005. We will be ready and excited to meet Kaierau in the final next week," Peina said.
MTA's chances were not helped with what appeared a serious injury to classy defender Kelera Kuruyabaki.
"Kelera going off midway through the first quarter didn't help, but all credit to Kaiwhaiki, they deserved their win last night," MTA coach Deshannon Matthews said.
"It looks like she's suffered ligament damage in her knee and is in a brace, but won't know more until the swelling goes down. Mt girls played well though and my standout had to be young 14-year-old Te Whetu O Te Ata Matthews-Koro who played exceptional netball against experienced Kaiwhaiki captain Kahureremoa Aki.
"I guess we faded off at the business end of the competition, but we're still in the play-off for third and fourth against WHs next week and that's out focus now," Matthews said.
Meanwhile, Kaierau head coach Walter Edmonds said lowering the error rate certainly paved the way to a spot in the final.
"WHS A1 tested my girls in every area of the court last night and the game went down to the wire, both teams I thought played real attacking games," Edmonds said.
"For us, it was about hitting our optimum in both attack and defence, staying in control and lowering our error rate. We can probably tick off two of those three things but we'll be hoping to tick all three off when we take the court next week."
WHS coach Lisa Murphy was far from disappointed by Monday night's result.
"Sitting in the spectators stand come finals night is not where I wanted to be, but I'm really proud of my girls, they never gave in, never let their heads drop," Murphy said.
"It will be the first time WHS hasn't been in a final since I've been coaching them and that may well be for the entire eight years they did make it. I've got a mix of younger players and more experienced heads and while we did have a few injuries, I'm not making any excuses.
"I started Year 10 student Kara Adrole at goal defence alongside Year 13 Catherine Nuaga, who was having her first match at this level. Catherine came to us from Whanganui Girls College and is an exceptional player, but is not used the pressures of semi-final netball at premier level. I started with them because I need the height at that end of the court.
"Then my shooter Montel Vaiao Aki went off with a knee injury in the last five minutes, which didn't help.
"It's great for Whanganui netball though, to have such a close run competition this season," Murphy said.