Western Australia has lost an incredible 8-1 — with its one run coming from a wide — in a batting collapse that has left the One-Day Cup champions' defence in tatters.

The Warriors were bowled out for 53 in 20.1 overs at the WACA Ground against a rampant Tasmania attack led superbly by Beau Webster (6-17 off six overs).

It was the second lowest score in One-Day Cup history, only narrowly bettering the 51 posted by South Australia against Tasmania in Hobart in 2003.

WA was crawling along at 2-52 in the 16th over of Friday's match before suffering one of the worst batting collapses witnessed in professional cricket.

In the space of 34 legal deliveries, WA lost eight wickets and registered just one run — in the sundries column — as Webster and Billy Stanlake (3-12) ran rampant.

It meant WA went from 2-52 to all out for 53.

The out-of-form Cameron Bancroft (14 off 29 balls) was the first to fall among the collapse when trapped lbw by Webster.

Ashton Turner was out lbw to Webster two balls later, and Josh Inglis was bowled by Stanlake one ball after that.

Cooper Connolly, Hilton Cartwright, Ashton Agar, Jhye Richardson and Joel Paris all posted ducks as WA's innings was brought to a crashing end.

Warriors opener D'Arcy Short was the top scorer with 22 in a sorry-looking scoreboard for the three-time defending champions.

WA's bid for a fourth consecutive title is now hanging by a thread.

The collapse likely means WA now needs to beat Victoria, South Australia and Queensland in its remaining three games — and rely on other results — in order to secure a top-two spot and a berth in the March 1 final.

WA fell short of its previous lowest score, the 59 posted against Victoria at the MCG in 1969.

Webster was the hero for Tasmania, claiming the early scalp of Short before kick-starting the collapse in a career-best display.

Stanlake was also hugely effective, with his pearler to bowl Inglis one of the highlights of the innings.

Tasmania reached the total in 8.3 overs, losing three wickets in the process.

AAP