St Just's hopes of a first Premier League title since 2009 suffered a big blow with a seven-wicket home defeat to leaders Werrington on Saturday.
The defeat by the reigning champions capped a nightmare week for the Cape Road side, who saw their nine-year unbeaten run in the Vinter Cup ended with a five-wicket defeat to local rivals Paul.
With Werrington winning a useful toss on Saturday, St Just could muster only 110 after being asked to bat first, Mark George top scoring with 36.
Werrington's Alex Smeeth was in sublime form with the ball, taking six for 34 which included a hat-trick.
The visitors reached their target for the loss of only three wickets with Nick Ward making an unbeaten half century before retiring hurt with a hamstring injury.
* Paul will meet either Camborne or Truro in the last four of the Vinter Cup after knocking holders St Just out of the competition.
Cornwall all rounder Kelvin Snell hit 41 not out in their 108 for five, after 21 had been required for victory off three overs.
Falmouth beat Redruth by 25 runs in Thursday's other quarter-final.
The visitors made 138 for six before the hosts were dismissed for 113 with three balls remaining.
Falmouth will now play the winners of Wednesday night's Crofty/Holman v St Gluvias quarter-final in the last four.
Semi-final draw: Weds June 26: Falmouth v Crofty Holman or St Gluvias (at Troon); Mon Jul 1: Paul v Camborne (at Hayle) or Paul v Truro (at Redruth).
* For more action and reaction from the weekend's local cricket see this week's Cornishman.
