Fullback Tony Ensor showed his great speed to score the first and last second-half tries that took the game out of Green Island's reach at Bishopscourt.
Ensor scored a try in the first minute of the second spell to stretch Kaikorai's lead to 35-13, and when Green Island came close late in the spell he scored his second try to make the game safe.
The other key player for Kaikorai was second five-eighth Cam Rutherford, who brought belief back to his team with an intercept try when Green Island threatened to put a stranglehold on the game by scoring an early try.
Rutherford also kicked seven goals from nine attempts to score 22 of Kaikorai's points.
Kaikorai controlled the lineout through lock Andy Brun, who made seven clean takes, and No 8 Lee Allen, who made four at the back.
Flankers Adam Hill and Nathan Hull were effective in the loose and their accurate tackling stifled the Green Island attack. Prop Jim Stevenson was effective in the tight with his driving play and pick-and-go.
Kaikorai took an iron grip on the game when it scored 17 points in 7min late in the first spell to lead 30-13 at the break.
Flanker Tala Moli used his strength to score a try to lead Green Island's revival after 5min in the second spell. \
Green Island scored 15 points in 9min to reduce the gap to seven points, 35-28.
Powerhouse No 8 Junior Sala kept Green Island in touch when he scored his second try after 23min.
In the second spell Green Island concentrated its attacking moves through its powerful pack, leading to four tries and two bonus points.
First five-eighth Joe Bartlett kicked seven goals from 10 attempts to score 17 points.
Kaikorai 49 (Tony Ensor 2, Logan Moore 2, Matt Te Tana, Cam Rutherford tries; Rutherford 4 con, 3 pen), Green Island 42 (Junior Sala 2, Tala Moli, Josh Beer, Andre Clarke tries; Joe Bartlett 4 con, 3 pen). Kaikorai 30-13.
