Kangaroos, rested from a weekend off, were too strong for Suburbs as they sealed their second win over their rivals in just three weeks following their minor premiership decider victory in Round 22.
Forward Joel Marama opened the scoring for Roos, but Suburbs levelled matters through Chad Henley to make it 6-6 at half-time.
However, it was to be Suburbs last score of the game as Roos ran away with it in the second stanza thanks to further tries from Marama, Bradley Stephens, Jared Allen and Kieran Hayes.
Roos coach Michael White said he was delighted with his teams performance, especially their defensive effort to limit Suburbs to just one try.
Sometimes you dont know what to expect after a two-week break, but wed talked about starting off well, and our defence especially was really pleasing, said White.
Suburbs are a tough team and you have to be on your game or theyll turn you over, so really, I couldnt be more pleased.
Its a special feeling for everyone at the club, and has created a great sense of pride to become the first team to reach the grand final.
As much as it would be good to treat the grand final as just another game, in reality its obviously not.
For me, getting there is a combination of all the hard work weve put in over the past nine months, and a few other things which have come together.
Hopefully, whatever happens in the grand final, along with the clubs successes in other grades this season, weve laid a successful foundation for the coming years.
White also praised for five-eighth Jared Allen, who recently returned to the club after a spell at St. George Illawarra Dragons in the national Under 20s Holden Cup competition.
Jared is a young man still learning his trade, but hes certainly taken a bit of pressure off Robbie (Amber), and has stood up in these big games.
His main goal is to get an opportunity with the Northern Pride, and although it would be a loss for us if he was called up by the Pride, wed also be delighted for him at the same time.
Meanwhile, in the other semi-final, Yarrabah continued their amazing run of form to dump defending premiers Brothers out of this years competition.
The Seahawks have now won 10 of their last 11 games and ended Brothers dream of a third straight premiership with a nailbiting 30-28 win.
Yarrabah looked set for defeat when they trailed by 18 points at half-time, before producing a dazzling array of attacking play to score five second-half tries and edge into the lead.
There was still time for late drama though when Brothers thought they had snatched it at the death with a match-winning try just two minutes from time, but a knock-on was ruled.
Merton Richards, Theeran Pearson, Ross Maloney (pictured - photo courtesy of The Cairns Post), Wade Smith, Fenton Murgha and Jabalum Mundraby were the Seahawks try scorers, with Bert Harris slotting three conversions.
Yarrabah will now play Suburbs this Sunday in a do-or-die preliminary final, with the winner to take on Kangaroos in the grand final on 15 September.
2013 Bendigo Bank CDRL A Grade FINALS (Week 2) RESULTS
Sunday, September 1 Barlow Park, Cairns
Semi Final 1
Yarrabah Seahawks 30 (M. Richards, T. Pearson, Maloney, W. Smith, F. Murgha, Mundraby tries; Harris 3 goals) def. Brothers 28 (Kepa 2, Bann 2, Guilgo tries; Doolah 4 goals).
Semi Final 2
Kangaroos 28 (Marama 2, Stephens, Allen, Hayes tries; Amber 4 goals) def. Southern Suburbs 6 (Henley try; Whittle goal).
Other CDRL Finals matches
Kangaroos 34 (David 2, Ambrym 2, Lauenstein, Pabai tries; Kalanianau 4, Barba goals) def. Brothers 22 (De-Bruyen 3, J. Gibuma, G. Gibuma tries; J. Gibuma goal).
Mareeba 40 (Kose 2, Shave 2, Hayes, Mitchell, Dodd tries; Hunter 6 goals) def. Yarrabah 38 (Blight 2, Ambrym, Hari, Bulmer, Richards, Neal tries; Garrett 4, Ambrym goals).
Brothers 22 (Parmenter, Kepa, Petterwood, Hodge tries; Farrow 2, Hodge goals) def. Tully 18 (Steptoe 2, Solien tries; Solien 2, Ketchell goals).
Kangaroos 48 (Gibuma 2, Lewis, Doi, Marama, John, Anau, Stephen tries; Morrison-Sailor 4, Doi, Anau goals) def. Innisfail 30 (Snowball 2, Anning, Skeen, Roos, Massey tries; Skeen 2, Kelly goals).
Ivanhoes 36 (B. Pye 2, Munster, Hari, J. Pye, Snider, Brian tries; B. Pye 4 goals) def. Mossman 32 (Nandy 3, Ryan, Burchell tries; Ryan 4 goals).
Malanda 28 (English, OBrien, Ball, Murgha, Fox tries; Ball 4 goals) def. Brothers 22 (Temu 2, Nasslander 2, Tabuai tries; Temu goal)