Rockingham-Mandurah have a challenge ahead of them when they take on ladder-leaders Claremont-Nedlands on day two of their clash.
The Mariners won the toss and elected to bowl on one day, getting Claremont-Nedlands all out for 261.
The pick of the bowlers were Adam France with 4-49 off 16 overs and Leon Coombs with 3-65 off 19 overs.
"It turned out to be a great toss to win... we had them 4 for 32 at the first break," coach Kris Kennedy said.
"Our bowlers executed consistently throughout the day but [Claremont-Nedland's] partnerships put the pressure on us.
"We just weren't able to take wickets consistently throughout our bottom order.
"Going into this weekend, we're just going to need a really disciplined effort, and it's important that we bat out our full 90 overs."
Day two of their match gets underway on Saturday at Cresswell Park.