Harvey-Brunswick-Leschenault is now one win away from claiming the 2019 South West Football League premiership title.
Playing at Brunswick Oval, the Lions faced off against an intimidating Boomers' line up on Sunday afternoon.
Eaton hit the ground running, before kicking two goals to one in the opening quarter.
After taking back control in the second term, HBL secured a four-point lead at the main break.
The home side rallied to post another three goals to two in the third quarter.
Following an explosive final term, the Lions celebrated an emphatic 7.12 (54) to 6.7 (43) win.
Eaton's Brandon Jetta kicked six majors, while HBL's Zachariah Piper scored two.
The Boomers will contend with Donnybrook in this Sunday's preliminary final at Hands Oval.
Last weekend, the Dons travelled to Payne Park for their showdown against Bunbury.
Chris Atthowe (two) and Tyler Patterson (one) put Donnybrook in front, before Bulldogs Tyson Wood and Matthew Martin levelled the scores.
Up by seven at quarter time, Sean Lynch (one) and Dion Parker (one) extended the visitors' lead to 18 in the second term.
Struggling to keep up, the Bulldogs fell further behind in the third quarter.
Donnybrook stormed home to claim a 9.9 (63) to 7.8 (50) win - knocking Bunbury out of the finals.
A blistering fourth quarter led Bunbury's Women's side to a nine-point victory against the Harvey Bulls.
Behind by eight at quarter time, the Bulls picked up steam in the second term.
Kicking two goals to one in the third, Harvey trailed by two points at the final change.
Bunbury slotted two goals in the fourth, before Harmony Staszewski-Hose got one back for the Bulls.
Winning 5.5 (35) to 4.2 (26), the Bulldogs will take on South Bunbury in the grand final.
Busselton's Reserves moved through to the grand final, after beating HBL, 9.11 (65) to 9.4 (58), at Brunswick Oval.
Dylan Patterson (three) and four other Magpies hit the scoreboard in Sunday's clash.
Joshua Kelly (three) and Stephen Kane (three) guided Eaton to a 13.15 (93) to 9.1 (55) win over South Bunbury
Bunbury's Colts look set to win their third consecutive premiership title.
Zachary Birch scored seven goals in the Bulldogs' 15.3 (93) to 8.9 (57) win over Busselton, at Payne Park.
South Bunbury did enough to crush the Boomers, 12.10 (82) to 9.6 (60).
Troy Bennell claimed three goals for the Tigers, while Eaton's Tanner Allen top scored with five.