Illawarra won the toss and elected to bat first, posting 127 from their 37 overs.

In the innings, the hosts were led by Ryan Cattle (33) and Bailey Abela (29), while Luke Gallen (2/27), Riley O'Carroll (2/10) and Max Carr-McCarron (2/16) all took two wickets for the visitors.

In reply, an unbeaten half century by opener Jackson Ingram (61 not out) steered Shoalhaven to the seven-wicket win.

In the chase, Ingram was well supported by both Patrick Higgins (26) and Jared Galvin (22 not out) - with Abela taking 2/18 for Illawarra.

In the other round one match, South Coast defeated Highlands (5/184 to 9/173) at Gerry Emery Oval, thanks to Luke Bramble (65) and Aiden Formosa (3/27).

Next week, in round two, Shoalhaven host South Coast at the Berry Sports Complex and Highlands battle Illawarra at Welby Park.

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The under 12s Inter Association also kicked off on Sunday, seeing Shoalhaven and Illawarra chalk up wins.

Shoallhaven won the toss against Highlands at Centennial Park and batted first - making 8/191 from their 40 overs.

Tobias Eyland (68) was the star of the innings, with Bailey Parker (33) and Flynn Dunn (22) also batting strongly.

Annalee Watson (3/29) and Hamish Murray (2/13) were the pick of the bowlers for Highlands.

In response, the hosts were cruising thanks to knocks from Rohan Day (43), Watson (30), Sam Harwood (27) and Mali Cassar (20).

But Highlands lost their four wickets for just 13 runs, to finish at 8/184 - seven runs short of the target.

In the win, Jesse Walters (3/11) and Eyland (3/36) claimed three scalps each.

The other match saw Illawarra edge South Coast (3/160 to 7/157) at Keith Grey Oval - on the back of 83 from Blake Cattle.

Next round, Shoalhaven take on South Coast and Illawarra lock horns with Highlands.

The final competition to begin on Sunday was the under 13s Inter Association, which saw Shoalhaven fall to South Coast (2/136 to 9/133) at the Bernie Regan Sporting Complex.

Standouts for the victors were Black Mackrell (65 not out), Baxter McDonald (55 not out) and Darcy Norris (4/9), while Shoalhaven was best served by Ryan Malecki (48 and 1/12), Riley Ingram (35) and Campbell Bramley (1/28).

Illawarra downed the Cavaliers (5/289 to 64) in the round's other match at Thomas Dalton Park - with Joshua Garnero (101 not out) and Alby Ferguson (3/13) starring.

Next week, South Coast clash with Cavaliers and Illawarra entertain Shoalhaven.

Sunday also marked the final round match of the under 16s competition, with both Twenty20 matches being played at Tom Willoughby Oval.

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South Coast defeated Illawarra (6/166 to 6/94) in the first match - with Liam Mackrell (44) and Mitchell Constantinou (2/15) leading the way.

Game two was won by Shoalhaven, who ousted Highlands (4/157 to 9/105) - behind strong play from Riley Sims (47) and Cooper Bramley (2/10).

These results mean South Coast and Shoalhaven will square off this Sunday in the final, at Geoff Shaw Oval from 10am.

While Illawarra and Highlands clash at King George Oval for third place.