Just the opening day's play was possible in the three-day carnival with heavy rain forcing a washout on Sunday and yesterday in the tournament featuring some of the top under-21 talent in NSW country cricket.

Hosts Illawarra went into the carnival seeded fifth out of the eight country zones, but their victory over fourth-seeded Western Zone will earn them a top four seeding for next year's championships.

"Having that one win and a top-four seeding is a good thing to have if rain again is a factor," Illawarra Colts coach and regional director of coaching Steve Davies said.

With most of the squad eligible for the Colts next year, Davies said there was strong base of talented players progressing from Illawarra junior representative teams to the Colts and senior side.

"We are in good shape with the likes of the McDevitt brothers [Joe and Xavier], plus Ben Chapman played NSW under 17s this season.

"Tylar Edwards played for the ACT under 17s and our Bradman Cup [under 16s] skipper Daniel Constable is a terrific young batsman.

"Against Western, our bowling was economical and, while we made some blues early on in the field, we picked it up with a couple of run-outs from direct hits at the back end, and with the bat the McCrae brothers were outstanding."

Illawarra restricted Western to 7-172 from their 50 overs before Hayden McCrae (67 not out) and his opening batsman brother Mitchell (45) led Illawarra to a four wicket win, with almost seven overs to spare.

Third seeds Southern Zone (6-221) thrashed Central North (149) in their only match, with Oak Flats teammates Kieran Gray (89) and opening partner Mick Arblaster (34) putting on 122, in a 72-run victory.

Prospective coaches are invited to a Level 1 coaching course run by Davies and South Coast regional coaching director Matt Faint at North Dalton Park on February 24. Details are on the Cricket NSW website.