The Kangaroos will now enjoy a well-earned break and advance directly to the grand final in two weeks, while the Blues will play West Belconnen next week in the preliminary final after the 32-12 loss.

Kangaroos player-coach Aaron Gorrell said it was nice to book a place in the decider but insisted his side still had plenty of work to do.

"We can't get too carried away, we've done everything we've needed to, but come a fortnight's time it all means nothing. It comes down to 80-plus minutes and we know they're going to be better for that if it's them or Westies."

His team has now won 16 straight games, but Gorrell said both West Belconnen and the Blues would be tough opponents.

"They're both quality sides and they've been close games every time we've played both of them," he said.

"Sometimes it can work against you, you've got a week off and they've got a bit of momentum."

Blues coach Simon Woolford was disappointed and said his side needed to be more clinical if they were to push for the premiership.

"Both teams turned up ready to go, that first half hour was pretty brutal and they broke our back with two or three tries off kicks and we didn't really bounce back," he said.

"And in the second half they had a lot more ball than us and it told on us in the end. They had 40 sets to our 25, or something like that, so they thoroughly deserve that win and we have to regroup now.

"You would certainly like to be the first one in to the grand final, I'm not going to deny that, but we have to regroup now, so we'll get ready for West Belconnen next week."

The result sets up an intriguing encounter between West Belconnen and the Blues, who have shared the honours this season with a win apiece.

Kangaroos 32 (B Crisp, B Cronan, S Dunn, J Pearce, T Whiley tries; B Crisp 6 goals) bt Blues 12 (J Lenihan, T Stevens, tries; L Berkrey 2 goals).