Chasing 217 for victory from what became a rain-reduced 58 overs on Wednesday, the Tigers reached the victory target with 26 balls to spare as rain clouds hovered close to the ground.

Charlie Wakim (50 off 81 balls) and Caleb Jewell (52 off 51 balls) produced handy knocks to set up the successful run chase, while Jarrod Freeman (21no) and Jake Doran (19) held their nerve after Tasmania had fallen to 6-186.

Siddle, who hit the winning runs after Doran was dismissed late, wound back the clock earlier in the day by snaring 5-40 to dismiss WA for 230 shortly after lunch.

"It's been a while since I got one (a five-for) in Australia. It's my first one for Tassie, which is nice," Siddle said.

"Coming here this morning we didn't know what was going to eventuate. So to bowl WA out and be in a position to win the game was a starting point.

"We didn't know how long we were going to have, light has played a part throughout the game, as well as rain.

"Both held off long enough for us to get the result, which is great."

Under normal conditions Tasmania would have had a minimum of 70 overs to achieve the victory target, but a number of rain delays saw that number whittled down to just 58.

The rain held off for the final session and the Tigers kept the runs ticking over to ensure the required run rate never got out of hand.

Earlier, WA had lost 5-26 in a disastrous start to the final day to be in all sorts of trouble at 7-155, with a lead of just 141.

But tail-ender Jhye Richardson (50 no off 59 balls) and Joel Paris (27 off 69 balls) came to the rescue with an invaluable 72-run stand to propel WA back into the contest.

Richardson was forced to sit out days two and three after suffering a back spasm while warming up on Monday.

But he didn't show any signs of soreness during his blistering knock, and he returned figures of 2-37 off 14 overs with the ball.

"It was a fantastic game of cricket," Richardson said.

"It was disappointing we couldn't get over the line, but a wicket like that produces a result and that's what we want.

"I found looking to score was probably the way to go about it instead of shutting up shop.

"The idea was to go out there and try to hit some quick runs, but that's the way I like to go about it anyway. "

Australian Associated Press