Old Boys have turned a first-innings defeat into an outright win against City United at No 1 Oval to secure a seventh-straight grand final appearance.
The reigning premiers now have a shot at back-to-back premierships and their sixth title in seven seasons.
Awaiting them in the grand final will be either City United or Bective East, who beat North Tamworth by 125 runs in the minor semi-final at Riverside 1 on the weekend.
Against City United, minor premiers Old Boys had to come from behind after City shaded them in a low-scoring first innings in the major semi-final.
After winning the toss and batting on Saturday, Old Boys were dismissed for 78.
In reply, City made 81.
With the match evenly poised, Old Boys needed to score quick runs on Sunday and then bowl out City to claim the outright win.
Enter Aaron Hazlewood.
After taking 5-26 off 20 overs, the allrounder produced a 44-ball 85 not out to propel his side to 4-162 declared off 17.4 overs in idyllic autumn weather on Sunday.
His innings was peppered with nine sixes and two fours. He teed off on almost every delivery and regularly cleared the picket fence and landed the ball on Kable Avenue.
Out-of-form Old Boys opener Simon Norvill then delivered with the ball. Bowling medium pace, the veteran claimed 6-23 off 15 overs as City were dismissed for 111 in 61 overs.
Hazlewood - the elder brother of Test star Josh - took 2-13 off 11 overs in a man-of-the-match performance.
City quick Tait Jordan snared 4-25 off nines overs in the first innings and took six for the match.
Old Boys captain Ben Middlebrook said he was confident of winning if "we gave ourselves enough time".
"Everything worked out, so it was great," he said, adding: "The way the boys fought back: I just can't speak enough [positive] words [about them].
I'm just really proud of them at the moment.Ben Middlebrook
"I'm just really proud of them at the moment."