Queensland went to stumps on day two at 3-185 in reply to WA's 465, with Jack Clayton (52 not out off 112 balls) and Ben McDermott (11no off 33 balls) at the crease.
Labuschagne (77 off 96 balls) cracked 12 fours and one six in a promising knock before being trapped lbw by spinner Corey Rocchiccioli (1-61).
But opener Matt Renshaw (six off 24 balls) was out cheaply in a blow to his hopes of pushing his case for a Test call-up.
Matt Renshaw was out for six in his first chance to impress national selectors this summer. (Richard Wainwright/AAP PHOTOS)
Renshaw was caught at third slip off the bowling of Cameron Gannon (2-33), with Usman Khawaja (31) also falling to the WA paceman.
Labuschagne's half-century represents a good warm-up ahead of Australia's five-Test series against India, which begins at Perth's Optus Stadium on November 22.
The 30-year-old also provided a comical moment while bowling when he tugged on Tom Straker's pants several times to get his teammate to field in the unusual position at the start of his run-up.
The bouncer barrage Labuschagne unleashed with his medium pacers had its desired effect when he found the edge of Gannon (53).
'I don't think I've ever seen that!' — cricket.com.au (@cricketcomau) October 9, 2024Marnus Labuschagne as #SheffieldShield captain is an experience 😂Watch his full (and very entertaining) three-over spell from day one at the WACA: https://t.co/5oPc5eu6Jn pic.twitter.com/OCE2vNcxKR
And Labuschagne had a second wicket courtesy of a stunning piece of fielding from Neser to dismiss Brody Couch (31).
Neser leapt in the air to take the catch on the boundary, threw the ball back into play as he went over the rope, before scrambling to catch the ball again.
It meant Labuschagne finished with figures of 2-5 from 6.2 overs.
Neser was the pick of the bowlers with 5-68 off 25 overs, with all of his wickets coming on day one.
Earlier, WA resumed play at 7-319 following opening-day centuries to Josh Inglis (122 off 117 balls) and Sam Whiteman (102 off 237 balls).
The runs continued to flow on Wednesday as rising star Cooper Connolly (79 off 104 balls) combined well with tailenders Gannon and Couch to frustrate the Queensland attack.
Connolly's knock was finally ended when he was caught in the deep off the bowling of Renshaw (2-43).
Gannon's second half-century of his first-class career was a huge bonus for WA.
"It's kind of found money when a guy like me scores runs, so I guess that's nice," Gannon said.
"But at the end of the day I'm here to bowl, and bowling well is what I love to do.
"A few weeks ago I didn't know where they were going, but we've figured it out, and they're coming out nicely at the moment."
