Eastbourne Eagles stifled a determined Lakeside Hammers side to earn a 53-39 second-leg win and a 99-86 aggregate victory at Arlington.
The Hammers took a slender one-point lead to the south coast, but were blown away by Cameron Woodward's 14 and Bjarne Pedersen's 13-point hauls.
Lakeside kept within five points of the aggregate score until heat 12.
But the Eagles secured a play-off final against Poole Pirates with 14 points in the last three races.
Eastbourne Eagles 53 (99): Bjarne Pedersen 13, Simon Gustafsson 6+3, Rider Replacement, Lewis Bridger 11, Joonas Kylamkorpi 7, Cameron Woodward 14, Timo Lahti 2
Lakeside Hammers 39 (86): Lee Richardson 11, Rider Replacement, Stuart Robson 1, Jonas Davidsson 4, Peter Ljung 10, Robert Mear 8, Kim Nilsson 1