Noradjuha-Toolondo avenged last year's grand final loss to Rupanyup-Minyup, comprehensively beating the reigning premiers by eight wickets on Saturday.
It was a dominant performance in the field from the Bullants, rolling last year's premiers for 120.
Batsman Rowan Scott praised his team-mates for their brilliant first-up effort.
"We held most of our catches and the boys bowled nice and tight," he said.
"Kyle Murray did a good job in the field and Wayne McDonald bowled really well with his off-spinners.
"Justin Combe was also very economical but it was just a good team effort."
Wickets were spread for the Bullants, with Scott, McDonald, Justin and David Combe all taking two wickets apiece.
Scott opened the batting and made an impressive 47 before Matthew Combe, 42 not out, and Ben Anson, 16 not out, guided the Bullants home with eight wickets and eight overs to spare.
Laharum notched up its first A Grade win with a comfortable five-wicket triumph over Horsham Saints at Laharum.
Last year's B grade premiers were impressive with both bat and ball, led by all-rounder Damien Bunworth.
Bunworth took three wickets and blasted a quickfire 48 not out to lead an undermanned Laharum to victory.
Glenn Doyle was also at his destructive best, smashing 54, including four massive sixes off debutant spinner Jordan McArdle.
Horsham's target of 174 wasn't enough, with a slow middle period leading to its downfall.
Saints skipper Gary Davidson said he couldn't blame the players for their efforts. "Everyone tried their hardest but it just wasn't our day in the field," he said.
"The Laharum batsmen were just too good.
"Our bowlers will need to work on their length during the week."
Homers defeated a youthful Colts side by seven wickets.
The visitors restricted Colts to 9-140, with Chris Hopper and Lachlan Jones each claiming three scalps.
Sandy Hodge and Adam Attwood both came agonisingly close to half centuries in the Homers' run chase.
Hodge, 48, and Attwood, 49, were both dismissed by Drew Carmody.
Experienced all-rounder Steve Kenny led Jung Tigers to a five-wicket win over Blackheath-Dimboola.
Kenny took 4-25 off his 10 overs and scored an unbeaten 44 to give the Tigers the perfect start to the season.