Stone admitted they should have posted more points as well, with the amount of good field possession they had during the game.
The game was a seesaw affair from start to finish with the lead changing on five separate occasions.
Greerton were the first to post points when giant flanker Joe Tupe broke a tackle before going 20m to score under the posts.
However, Whaka hit back with two tries before the break and on both occasions showed more willingness to get to the ball than the Greerton defence.
Unfortunately, the halftime break proved beneficial for Greerton Marist who came out on fire in the second half.
Whaka struggled to make it out of their own half for the first 15 minutes following the break and Greerton made the most of the pressure, scoring two tries.
The game seemed to be going Greerton's way until substitute Chris van der Vlugt came on for Whaka, making a 40m burst down the right side which set the home team up for their third try.
Centre James O'Neill finished off the try after a nice cut out ball from Maurice Stone jnr, who injured his shoulder late in the game.
Some sloppy kicking from Greerton Marist meant Whaka took the lead 21-17, following the conversion.
However, with about three minutes to go Whaka found themselves defending their own try line once again.
Phase after phase of Greerton attack tried to pierce the Whaka defence but the home side looked solid, until a heart-breaking run from Greerton fullback Alex Jessop.
Jessop snatched the ball from the back of the ruck and used his strength and pace to find a hole on the short side, winning the game for the visitors 22-21.
In other premier games, Mount Maunganui 67 v Paroa 25, Rotoiti 12 v Rangataua 8, Opotiki 25 v Te Puke 21 and Tauranga Sports 53 v Te Puna 13.
Whakarewarewa 21 (Bauro Kairaoi, Chris Miller, James O'Neill tries; Maurice Stone Jnr 3 cons) defeated by Greerton Marist 22 (Alex Jessop 2, Joe Tupe, Matt Ropoama tries; Alex Jessop 1 con).