The matched ended with Cunningham slotting his fourth penalty goal to give Rotoiti a 19-13 victory and maintain their unbeaten start to the season.
The home side picked up a bonus point courtesy of finishing within seven points of the visitors.
Rotoiti player/co-coach Wayne Ormond was happy to have come through the "pretty physical game" with a win.
"It could have gone either way but we were lucky it went our way," he said.
With two men being sent off, Ormond admitted his side would need to work on their discipline ahead of their next match, against Opotiki.
Discipline aside, Ormond was pleased with how his team performed away from home in what he described as a tough competition.
"The senior players pulled off a big game," he said.
"There's extra pressure playing away but they weathered it."
Defending Premier champions Te Puke Sports ran riot over Greerton Marist at Te Puke headquarters, with an emphatic 68-7 victory.
Two tries apiece to Simon Chisholm, Fred Ovrabah and Mark Nicolaas, who came on in the second spell, led the way for the home side with Chub Hale, Ryan Lambert, Mike Flood and Ben Ward also dotting the ball down. Nick McCashin had his kicking boots on, converting nine of the Te Puke tries.
Tauranga Sports posted their first win of the season, when they took out the Western Bay battle of the bridge 25-10 against Mount Maunganui.
Opotiki continued their sterling start to the season racing away from Rangataua 45-5 in the Eastern Bay of Plenty.
On Friday, Whakarewarewa withstood a spirited challenge from neighbours Waikite before banking a 26-24 victory.