Player-coach Ra Broughton said it was about applying pressure to YMP, and the tactic paid dividends when Waikohu blindside flanker Adrian Wyrill recovered his team's overthrown lineout ball to score next.
YMP again responded quickly, catching their own kick-off and setting up winger Te Peehi Fairlie for a dazzling individual try in the right-hand corner in the first phase.
Waikohu worked the ball back into YMP's defensive zone before a quick tap by Ra Broughton was punished by a thumping tackle. However, YMP were not back 10 metres and the resulting scrum from the penalty gave Waikohu the chance they needed.
No.8 Ngahiwi Manuel took the ball off the back and passed to first receiver on the blind side, James Rutene, who crashed over for the try.
The YMP forwards rumbled up the middle but a double movement meant the ensuing try was disallowed, and Waikohu led 21-17 at the break.
The second half brought much more of the same, with both sides playing strong attacking rugby.
Waikohu prop Jarryd Broughton made a punishing run, travelling several metres after contact to score.
YMP recovered their own kick-off again, with a messy reception from Waikohu, and second-five Louis Devery making a strong run to score between the posts.
A stunning individual effort by fullback Ethine Reeves to hold the ball up over the line kept Waikohu ahead as time ticked down in the second half.
But the constant pressure from YMP proved too much. Using the same move Waikohu had used in the first half, No.8 Jess Kapene took the ball blindside off the scrum and passed to fullback Andrew Tauatevalu. He reached out in the tackle and dotted the ball on the line to put YMP ahead with less than 10 minutes to go.
The intensity Waikohu mustered in the final minutes showed how much they wanted to keep their perfect season intact. It wasn't enough, though, and YMP held on to win.
YMP head coach Brian Leach said a large part of his team's success came down to the forwards winning the battle up front.
“Our boys were unreal,” he said.
The YMP player of the day was No.8 Jess Kapene, who also took out the match most valuable player (MVP) award.
The experiment of playing Saul Chase at lock for YMP has had a rocky start. In his second game there after moving into the forwards from the outside backs, he was concussed. He will now be sidelined for a mandatory two weeks.
Ra Broughton said Waikohu saw the loss in a positive light. They “needed it in a way” to keep them focused.
However, he didn't want to take anything away from YMP, whom he congratulated for playing a “great, passionate game of rugby”.