Jhye Richardson's case to play in the first Ashes Test is getting stronger by the day after he ripped through Tasmania's middle-order to help give Western Australia a healthy lead heading into the final day at Bellerive Oval.

Richardson took 4 for 53 to help bowl Tasmania out for 317, giving him 12 wickets in his last three Shield innings and 20 for the season in just four games. Cameron Green then tuned up for the Ashes with a fine unbeaten half-century to give WA a lead of 258 heading into the final day.

Richardson produced a stunning burst with the second new ball early on day three nicking off Ben McDermott and Jake Doran as Tasmania collapsed from 2 for 214 to 9 for 259. Cameron Gannon and Matthew Kelly picked up five wickets between them in the aftermath of Richardson's burst.

But Jordan Silk made a defiant 73 to ensure the first-innings deficit was under 100. He added 58 for the 10th wicket with Gabe Bell who contributed just 8 runs. WA pushed nearly all their fielders into the deep and Silk picked them apart with some intelligent batting.

WA started their second innings strongly with a 69-run opening stand between Cameron Bancroft and Jayden Goodwin before offspinner Jarrod Freeman struck twice in back-to-back overs. Sam Whiteman could not back up his first-innings century edging Peter Siddle behind for 13 but Green steadied alongside Hilton Cartwright. The pair put on 70 before Cartwright fell late in the day. Green struck six boundaries in his half-century and is well placed alongside Josh Philippe to tee off on the fourth morning as WA push for a declaration.