The Illawarriors were on song in the first game against Central Coast, wearing down the visitors to win 27-5.

Central Coast took on Balmain immediately after the opening clash, while the Warriors did their best to stay loose before meeting Balmain in the final match of the day.

But Illawarra's 40-minute lay-off worked to their opponents' advantage and Balmain claimed a 10-5 win. "We had two 30-minute halves against Central Coast and then had a 40-minute break and the boys stiffened up a bit," Illawarra forward Paul Tuala said.

"A lot of our structure and connections worked well in the first game, but in the second game the boys were a bit cold and stiff and we didn't have that same rhythm.

"There was a lot of positives but obviously a few things we can work on. Everyone got a crack at their positions and a few of the boys got put out of position just so [coach] Shaun [McCreedy] could see what they can do."

The Illawarriors are working toward playing their best rugby at the NSW Country Championships on May 2-3 at Bowral. Illawarra were last crowned Country champions in 2004.

McCreedy believes his side has progressed since a 21-0 trial win over Sydney University earlier this month.

"I was very happy with the way Saturday went for us," he said.

"We achieved some goals and it was a good hitout for us to see where we're at and where we need to improve.

"We took the approach that we wanted to be quite physical with Balmain.

"They had some quality backs in there, so we wanted to take them on up front and upset their rhythm a bit, which I felt we did pretty well.

"We've got a month to go away and work on areas we need to improve and also just consolidate a lot of the stuff we've been improving since our first trial."

In other Illawarra rugby news, Campbelltown have returned to the competition after a 14-year hiatus.

The first grade competition consists of 10 teams, with the opening round of games on April 11.

Standing out in the first round is the grand final rematch between 2014 premiers University and runners-up Camden at Camden Rugby Park.