Manawatu's beaten Tasman 27-23 in Nelson to stay on top of the Championship in provincial Rugby's ITM Cup.
The Turbos needed only a point to make sure of reaching next week's final with Hawke's Bay but Tasman led 17-10 at half-time and didn't concede the lead until the last five minutes.
Aaron Cruden sealed the win with his second try, and Manawatu's third, while Andrew Goodman converted both of Tasman's tries and kicked three penalties.