"It was a difficult loss for us to take because we dominated possession but just couldn't find the back of the net," he said.
"The first half was hard for us battling against the wind and Otumoetai used it to their advantage.
"The goal was very disappointing. It was a high lucky ball which unfortunately our two centre backs missed leading to a clear run on goal for their striker. It was always going to be hard playing against a very physical team and we didn't give quite enough as a team."
Cane said his attacking line-up was affected with the absence of captain and striker Kim Emmanuelle-Maguire, who was unavailable for selection.
"It was frustrating because we must have had about eight decent chances in the game but the keeper was in top form and kept us out," he said. "I can't say we were unlucky though because we didn't find the crucial couple of goals which you need to win games like that."
The result leaves Rotorua on 21 points and they now rely on other results going their way to win the league.
United will face bottom-of-the-table Waikato Unicol and the tricky re-scheduled fixture against this weekend's opponents in their two remaining matches.
"We must have a big final push from everyone," he said. "I don't expect Northern to slip up now but you never know what can happen in other games so we just have to put ourselves in the best possible position."
Results
WaiBOP Premier League:
Otumoetai Bay Sportsmed 1 Rotorua United 0
Northern United 7 Hamilton Wanderers 2
Waikato Unicol 0 Claudelands Rovers 9
Melville United - Bye
Women's Bay 1:
Plains Rangers 3 Ngongotaha 2
Taupo 9 Rotorua 0
Papamoa 1 Te Puke United 0
Kawerau Sports 1 Whakatane Town 2
WaiBOP Premier League points (top 4):
Northern United 22, Rotorua United 21, Otumoetai Bay 19, Melville United 19