Bobby Roberts' three goals to the Bulls' zero ensured his side would advance to the second week of the finals.

West Belconnen coach Troy Thompson was relieved to be victorious but frustrated with the way in which it happened, citing impatience for what he described as a scrappy win.

"That was one of our worst performances, to be honest," he said.

"Bulls played really good footy, they played structure, they probably completed 90 per cent of the sets. We didn't, we kept turning the ball over but they [West Belconnen] stuck in and got the win.

"Every time we were down in their half we just seemed to want to score a try off every set. We've just got to complete the sets, which is what we've been doing all year — just doing enough to win the games."

Bulls coach Lincoln Withers said his side had to defend for too long and it wore down his young team, but he was excited for what the group could develop into.

"The effort's always there, it's been there all year. We just weren't as clinical today," he said.

"Both our teams, first grade and second grade, they're all kids. Only one or two are over 24, so it shows good stead for the future if they can hang in there and back up next year.

"We scored the same amount of tries, they just had a lot of the ball, and defending took a lot of the petrol out of us."

West Belconnen will play the loser of Sunday's major semi-final between Queanbeyan Kangaroos and Queanbeyan Blues and Thompson said either team would be tough next week.

"At our best we're pretty competitive, so we have just got to stick with it. They're both strong all over the park, so I hope they just bash each other tomorrow," Thompson said.

CANBERRA RAIDERS CUP FIRST GRADE

ELIMINATION FINAL

West Belconnen Warriors 22 (R McQueen 2, S Finnegan, A Greenwood tries; R Roberts 3 goals) bt Gungahlin Bulls 16 (B Hill, D Low, R O'Sullivan, M Sollis tries).

Sunday: Major semi-final – Queanbeyan Kangaroos v Queanbeyan Blues at Freebody Oval, 3.15pm.