A select field of seven men including the promising U19 competitors Bunker and his training mate Boaz Darby started the 100km race and the pace was on from the outset.
On the second climb up the long Waimutu Rd hill, Cheatley attacked the bunch and rode clear a lead he held for much of the rest of lap two.
Eventually the bunch reeled him in, but on lap three Cheatley and Adam Gosney joined forces and working together strongly, building a decent gap through the Fern Flats and Tutaenui Rd sections of the course.
Their rivals weren't going to let them have it all their own way though, and with a concerted effort from Sturzaker, Bunker, Darby, Brent Bismark and Phil Groves they reconnected with the breakaway duo with about 8km to go.
Down the long straights of Turakina Valley Rd the usual 'cat and mouse' tactics played out but the bunch stayed together.
Inside the closing stages though, Bunker threw in an audacious attack that saw him shoot clear.
Approaching the finish his bold move looked to have paid off, but with a massive effort from the chasers he was swamped just short of the line.
Cheatley, as he has done so often previously, showed his class and got his wheel across first.
Sturzaker did all he could to retain his title, but in the end had to be content with second spot.
Adam Gosney was right there in third, having produced a quality ride for one who hasn't raced much recently.
Bunker clung on bravely for fourth placing snaring the U19 title and again underlining his considerable promise.
Brent Bismark was next in, with Darby and Groves just in behind the place-getters finishing sixth and seventh respectively.
Twelve riders contested the 50+ Masters race over 70km. Pat Johnstone was simply too strong for the field, riding away on lap two and grinding out an impressive victory by just under two minutes.
The course suits tough riders and Johnstone again showed why he has been a national age-group champion in the past.
The battle for second place was won by Steve Cowan, who produced his trademark sprint finish to head off last year's winner of this grade in Paul Forrest, who crossed third.
After a break, Darcy Forrester took fourth, just ahead of lightweight veteran John Black.
Ross McNeil rounded out the top six.
Notably Laurence Sunde produced a great ride for eighth against much younger rivals.
Unfortunately the woman's title could not be awarded as Catherine McMurray was the sole contestant.
She rode with the men's 50+ field in the 70km race and acquitted herself well against her male counterparts.
Results
Senior Men's Club Championship: 1. Bevan Cheatley (2:54.75); 2. Jason Sturzaker; 3. Adam Gosney.
Masters 50+ Club Championship: 1. Pat Johnstone (2:04.01); 2. Steve Cowan; 3. Paul Forrest.
