NSW's top-order fell in a heap as Western Australia's bowlers made significant in-roads in their rain-affected Sheffield Shield match in Sydney.
NSW advanced nervously at Bankstown Oval to be 5-55 at tea, still 301 runs in arrears.
In-form opener Daniel Hughes made just six before edging a Joel Paris outswinger to second slip.
WA then picked up the key scalp of Blues' captain Kurtis Patterson for 21 lbw to Mathew Kelly, before the same bowler struck in his next over to remove Jack Edwards for one.
Kelly (3-7) then reprised the feat for a third wicket in as many overs by bowling Hayden Kerr for a duck, before Paris (2-16) returned to clean bowl Baxter Holt for two.
Earlier, WA batted for another seven overs into the elongated afternoon session, adding 34 to their tally before declaring at 6-356.
Hilton Cartwright fell soon after lunch with his marathon 209-ball innings ending on 81, caught on the square-leg boundary after hooking a short Chris Tremain delivery (2-42).
Tremain's second wicket came a day and a half after his first with day two lost entirely due to ongoing showers.
The hard-hitting D'Arcy Short was the only WA batter that failed to reach double figures when he was caught and bowled by Kerr for one.
Aaron Hardie remained unbeaten on 37.
