WA's Second XI will need a big day with the bat on Wednesday after going in at stumps on day two at 2-102 in reply to New South Wales Second XI's 542 at Sydney's Hurstville Oval.
Poor weather meant several hours of play were lost on day two of the match, which has been organised while the Perth Scorchers and Sydney Sixers are away in South Africa for the Karbonn Smart Champions League.
Marcus Harris and Jason Behrendorff have been the star performers so far for the West Australians, with the opener unbeaten on 60 at stumps, while the bowler picked up 4-94.
On Behrendorff, WACA Development Coach Geoff Marsh said: "He bowled really well. Unfortunately we lost three hours of play due to weather and when he was running up it was very wet today, but he got through that. He bowled very well and Marcus Harris was good with the bat late in the day."
New South Wales were well-placed at stumps on day one on 4-395 after being sent in to bat and Kurtis Patterson picked up where he left off, moving from 103 to 149 before he was caught at cover.
Scott Henry had scored 104 on day one, while debutant Adam Semple kept the runs ticking on day two before reaching three figures, scoring 103 to frustrate the West Australian attack. NSW eventually declared at 7-542.
Former NSW bowler Burt Cockley picked up 1-90, Ashton Turner 1-88 and Matt Dixon 1-114.
In reply, Liam Davis was run out for five, while Sam Whiteman lost his wicket late in the day, trapped in front for 32.
Harris and Travis Birt will begin day three at the crease on 58 and four respectively.