The Kiwi Ferns have once again downed the Jillaroos in a best-of-three Nines series, running out 21-7 winners in the decider to again edge the series 2-1.

Speaking after the match, Kiwi Ferns captain Sarina Fiso said she was pleased that her side were able to stick to their gameplan.

"We knew we weren't the faster or fitter side, but it was just about doing our thing in that third game," Fiso said.

"We stuck with the plan from the first game and it paid off in the second game.

"It is awesome to win the series and we are very proud."

Jillaroos captain Steph Hancock offered a blunt assessment of her side's loss to the Kiwi Ferns.

"We weren't unlucky," Hancock told NRL.com.

"We just couldn't get it together and personally I think we can play a lot better as a team. Our communication was good but getting the ball out was a little bit unsavoury today."

End-to-end sets from both sides early in the game set the tone and the Ferns' first real attacking chance came midway through the set following a half break from Amber Kani.

After pressing the line for most of the set a wonderful chip from Georgia Hale out to Mary-Jane Ale's wing saw the rookie winger bag first points despite a questionable grounding in what was her second try of the day.

The Ferns got the ball back in Jillaroos territory from the restart with a minute left and a well-worked right side move saw Langi Veainu get around the outside of the defensive line to make it 8-0 at half time.

Desperately needing some luck to start the second half the Aussies got it through a pinpoint kick from Maddie Studdon. Ale was caught in two minds at the touch line and ended up tossing it infield where Jillaroo Annette Brander picked it up but she failed to find her supporting runner then passed from the ground to concede a penalty.

The Jillaroos got the ball back however and looked to have scored through Kezie Apps but the back-rower fumbled a tricky pickup with the line beckoning. 

They paid for the missed chances when the Ferns produced a huge set with the ball then Kristina Sue speared through a gap in the line near halfway and raced away to score next to the posts, although she appeared to injure her knee in the grounding.

The Aussies finally got on the board when a mid-field Allana Ferguson bomb was fumbled by Veainu and Kody House was on hand to pick up the scraps and race the last 20 metres to score in the bonus zone.

With time running out Aussie skipper Steph Hammond put her hand up for some big hit-ups but a miscommunication between fullback Sam Bremner and Apps turned over possession and Ferns skipper Sarina Fiso added an exclamation point to the series win when she scythed through under the posts for a 21-7 final score.

Kiwi Ferns 21 (Ale, Veainu, Sue, Fiso tries) def. Jillaroos 7 (House try).