Kakamora started off taking a 2-0 lead in the first half before adding another three later in the second half.
Coach George Fafale said this is a good start for them.
He also applauded Renbel for a good match.
"The win is a good start for us.
"It was a good match we achieved the result we wanted from the game plan we had in place.
"We however did not expect such a goal margin but Team Renbel played well and structured," he said.
Renbel coach Batram Suri has no big expectation from his boys because of the short time together before the competition.
He admitted using the opening match as a preparatory match for their remaining matches.
"It was not an easy match for us but we’ve learnt a lot from it.
"We need to work on some areas we see needs to be addressed and hopefully we will come back stronger on our remaining matches.
"Since we did not have any friendly matches before the competition I told the boys that we take this as our preparatory match and aim for a good start in our second group match," he said.
Kakamora now leads pool B with three points.
Pool B will continue matches tomorrow.
Meanwhile, in another match on Sunday Isabel Frigates has stunned Honiara Warriors with a 3-1 victory.
Two exciting matches are being lined up for matchday 3 today in group A.
Defending champions Malaita Eagles will meet their first real test against the Hornets at 1 pm.
For the main match, Western Tomoko will go up against the Temotu Arrows who have arrived yesterday morning.