Waikato have crashed to a third successive NPC loss, blowing a lead to be toppled 23-10 on home soil by Manawatu.
After scoring the cross-over game's first two tries and leading 10-3 with 25 minutes to play in Hamilton, Waikato frayed badly against their Championship division rivals.
More urgency and a superior scrum helped set up converted tries to Manawatu reserves Jamie Booth and Harrison Brewer before Jade Te Rure slotted two late penalties.
It was another disappointing result for Waikato, who were beaten 37-7 by Northland last week and have won just two of their six matches.
Manawatu have lost to Championship rivals Wellington, Otago, and Bay of Plenty this season yet have enjoyed success in their matches against top-tier Premiership opponents. Their other win came over Tasman in week two.
Saturday's scoreline would have been more emphatic, were it not for lock Tom Parsons inexplicably spilling the ball as he dived for the tryline following a sweeping Manawatu attack near the end.
Waikato scored early through centre Pita Ahki and extended their 5-3 halftime lead when reserve hooker Samisoni Taukei'aho drove over from a rolling maul.
Waikato will anxiously await an injury update on fullback Zac Guildford after the former All Blacks back suffered a hamstring injury and was replaced.