Chasing 333 to win, the Warriors were cruising at 1-121 but lost four key wickets in a little more than 10 overs - including a match-turning run out of skipper Ashton Turner - to hand the Vics the ascendency.

Victorian skipper Peter Handscomb and opener Marcus Harris had played crucial roles with the bat after the Vics won the toss, but it was their tail-enders who shone brightest as the last four wickets added more than 100 crucial runs to push the total well beyond the 300-mark.

The previously unbeaten Warriors had looked on course for victory when Josh Phillippe (28 from 14 balls), Josh Inglis (63) and in-form left-hander D'Arcy Short (44) were motoring along at better than 6.5 runs an over.

The circuit-breaker for Victoria came via a Jackson Coleman slower ball that Short tamely gloved down the leg side before Turner was caught short by a brilliant turn and throw from Glenn Maxwell, who chased and gathered a misfield and fired in a bullet return for wicketkeeper Handscomb to do the rest.

And when top-scorer Inglis was caught at point in the very next over, the momentum was firmly in Victoria's favour.

Marcus Stoinis briefly looked threatening until he pulled a Chris Tremain delivery straight to the fielder at deep mid-wicket before Coleman, Fawad Ahmed and Andrew Fekete brilliantly dried up the runs and the required rate sky-rocketed to beyond 12 runs an over.

WA's innings slowed to a crawl in the late overs, despite the two sixes Andrew Tye hit from his first two deliveries, as the Vics won by 63 runs to set up a showdown against Tasmania in the tournament decider at Junction Oval on Wednesday.

A bright spot on a disappointing day for WA was the performance of pace ace Nathan Coulter-Nile, who produced late swing and noticeable bounce to take two wickets in his first seven balls at the start of the match.

The right-armer, who on Friday earned a recall to Australia's T20 side, returned in the middle overs to bounce out Maxwell for just seven and he finished with 3-50 from his 10 overs.

WA's attention now turns to red ball, and a chance at redemption, when they host Victoria at the WACA Ground in the first round Sheffield Shield beginning on Tuesday 16 Otober.