Having been bowled out for 233 earlier in the day, Creek fired back with vengeance to reduce Eastlake to 5-30 at stumps on the opening day of the three-day clash at Kingston Oval on Friday.

Wests/UC has the box seat in the other Cricket ACT first-grade semi-final, resuming on Saturday at Freebody Oval at 3-170 chasing Queanbeyan's first innings total of 222.

Eastlake has lost just one game all season in the long format, but will rely on ACT Comets stars Vele Dukoski (two not out) and Michael Spaseski (yet to bat) to get them out of trouble.

Both are in fantastic form having blasted unbeaten centuries in last week's match against Queanbeyan.

Creek batsman Jono Dean - who top-scored for his side with a quick-fire 61 - knows the pair are capable of changing the game.

"We can't really ask much more to be in this position, but we saw what Vele and Spags did to Queanbeyan last week, so it's really important we don't take the foot off the gas," Dean said.

"If we get those two then we're right in the mix.

"Those two are capable of putting on 200, so we'll have to bowl well tomorrow."

Spaseski pushed himself down the batting order with a back injury after bowling 14 overs.

Creek captain Michael Delaney (2-5 from nine overs) and Djali Bloomfield (2-11 from five) were both outstanding with the new ball.

Eastlake quick Josh Bennett grabbed a five-wicket haul for the Demons, ably assisted by Lain Beckett with 3-40.

"It was going good until the last hour of play," Bennett said.

"There's a fair bit of grass coverage, so the pitch is good for bowlers.

"We've still got batting to go, so we're definitely not ruling out first innings, and even there's so much time left that there will be an outright result."

Opener Adam Heading got Creek off to a solid start with 49, while youngster Mac Wright put a high price on his wicket with 47 at the end of the innings.

At Freebody Oval, Queanbeyan was in early trouble before Lakshmn Shivakkumar steadied the innings with 78.

Wests/UC also lost wickets quickly, but a century-plus partnership between Blake McDonald (61no) and Adam Hewitt (56no) has put the defending champions in a good position.

"They had a fightback with the bat and 222 is probably sub-par, but you never know in a final," Wests/UC captain Ben Oakley said.

"We've steadied with a pretty good partnership so we're looking pretty good at this point.

"There's a lot of cricket left."

Douglas Cup semi-finals: Weston Creek Molonglo 233 v Eastlake 5-30 at Kingston Oval. Queanbeyan 222 v Wests/UC 3-170 at Freebody Oval. Play resumes on Saturday at 11am.