After last week's top-of-the-table win over Nyngan, CYMS were expected to easily account for the Roosters and they didn't disappoint with a ruthless 10-tries-to-one victory.

Fishies coach Tim Ryan strapped on the boots and played five-eighth in the absence of Blake Tremain-Cannon and said he was pleased to see his side put in such a clinical performance.

"We talked about it during the week and before the game. It was something we wanted to do, put in an 80-minute performance so that was good," he said.

"We haven't done it all year so it was good to do it today."

Daryl Cubby crossed the line five times but it was an impressive all-round effort from the Fishies as they kept hold of their spot at the top of the ladder.

After a quiet opening, 10 minutes the game exploded into life as a slick backline move was finished off by teenage winger Kaide Rapley. This was swiftly followed by an 80-metre runaway try to Colby Pellow and then Cubby's first to make it 18-0 after 18 minutes.

Alex Bonham, who was outstanding at halfback all match, made a darting crossfield run off a scrum and offloaded to Keiran Shipp to make it 24-0 before Shipp showed off some fancy footwork two minutes later to score his second and Pellow's perfect record with the boot continued to make it 30-0.

A smart run down the sideline from Rapley led to him scoring his second try and Pellow's first miss of the afternoon saw the score 34-0 at half-time with the Roosters hurting their own chances with rash decisions when in attacking areas.

Bonham picked up where he left off as the second half began and another break from the number seven put Cubby over before the centre grabbed his third when the Fishies worked the ball down the field again and a short ball from Luke Jenkins put him over.

The Roosters finally got on the board when Joseph McCarthy broke through and dived over out wide. However their joy was short lived as a minute later Bonham took an intercept on his own 30 metre line and raced away to score a well deserved four-pointer and take the score to 50.

Colt Tairua, not long with CYMS since moving to Dubbo from Cairns, continued his impressive start to life in green with a barnstorming try shortly after and from the kickoff Pellow made a 60-metres break down the wing before finding Cubby inside for his fourth try.

Some soft defence allowed Cubby through for his fifth five minutes from time. After the final whistle Cobar coach Nathan Graham said it was a hard day at the office for the understrength Roosters.

"At the moment it is a bit tough, we had six blokes who played reserve grade and had to back up and play first grade.

"We struggle as it is with blokes working in the mines but injuries, suspensions and stuff like that make it even tougher," he said.

"But to put in for the 80 minutes, the score might not reflect the effort we put in."

o DUBBO CYMS 66 (Daryl Cubby 5, Kaide Rapley 2, Keiran Shipp 2, Colby Pellow, Alex Bonham, Colt Tairua tries; Pellow 8 goals, Cubby 1 goal.) def COBAR ROOSTERS 4 (Joseph McCarthy try)