Essex 240 (Roelofsen 90, Westley 52, Waite 3-23) beat Yorkshire 76 for 6 (Snater 3-29) by 88 runs (DLS method)
Grant Roelofsen's sublime innings helped Essex to a third successive Royal London Cup win and bolstered their chances of qualifying for the knockout stages.
The South African recorded his third half-century in a row in the competition, finishing with a season's high of 90 off 97 balls before Essex's last eight wickets fell inside 14 overs for the addition of 56 runs.
Roelofsen put on 151 - the only significant partnership of the game - with Essex captain Tom Westley, whose 52 was his fourth successive score above fifty.
Yorkshire were soon in trouble in pursuit of 241, losing four wickets in the first six overs, and never recovered before heavy rain ended play - a relief not just for the Chelmsford outfield, but also or one of the most parched parts of the country. Essex, winning by 88 runs on DLS, leapfrogged Yorkshire into third place, though they have played a game more.
Roelofsen dominated the third-wicket stand. Though not afraid to improvise with the reverse-sweep, the most eye-catching of Roelofsen's impressive array of strokes was a punishing off-drive though the covers for one of eight fours.
There were two sixes for the South African in an over from Harry Sullivan over midwicket, and a third even more effortlessly off Matt Revis. At other times he was content to keep the scoreboard ticking along with nudges and flicks for singles and doubles.
Westley was very much the sleeping partner. His fifth boundary, clouted firmly past Revis, brought up not only his own fifty, but also 150 for the stand. However, without addition he miscued an attempted pull over midwicket and skied a return catch to Sullivan. Roelofsen perished not long after when he went for one reverse-sweep too many against Sullivan and picked out Shutt at backward point.
The pair had come together 25 overs earlier after Feroze Khushi was bowled by Ben Coad playing down the wrong line, and was followed almost immediately by opening partner Josh Rymell, run out on his call by a direct throw to the non-striker's end by Shutt fielding at mid-off.
However, the parting of Roelofsen and Westley prefaced a collapse from 184-2 to 240 all out.
Robin Das fell to a carbon-copy of Roelofsen's dismissal, chipping up Dom Bess to Coad. Nick Browne was bowled trying to give himself room against Shutt. Luc Benkenstein attempted to slog Waite and was bowled before Aron Nijjar was castled by Shutt. Waite mopped up the innings by having Jamal Richards caught behind and Ray Toole held one-handed at full stretch by Will Fraine at wide mid-on.
The target did not initially look onerous, but Yorkshire were quickly in trouble. Roelofsen, swapping batting pads for the wicketkeeper's, was soon back on the scorecard, catching Harry Duke behind off a faint tickle and then stumping Will Luxton, who tried to charge Nijjar.
Shane Snater then had Fraine edging to slip, and next ball trapped Jonathan Tattersall like a statue in his crease to claim his third wicket in 11 balls.
George Hill and Waite dug in doggedly for nine overs until Waite's 35-ball vigil for 15 ended when he was lbw to one that kept low from Toole. The New Zealand seamer followed that by finding the edge of Revis's bat and Yorkshire had fallen to 71-6.
Five runs later the players scuttled off as the first serious rainfall of an otherwise dry season quickly flooded the ground and forced Duckworth and Lewis into decisive action.
Tom Westley, expecting rain, had even slipped in a couple of rapid overs himself to ensure there would be a positive resut. "With 10 overs constituting a game, I brought myself on early. It started spitting in the sixth or seventh over and you could see clouds building everywhere so that was the reason why I came on for those token two overs.
"I suppose being bowled out before we had faced the full 50 overs went in our favour because it gave us a bit more time to move the game forward and give us a bit more time with the ball. It's pretty infuriating though that our number 11 is having to bat in every single game after we have got ourselves into some fantastic positions.
"We don't want to sell ourselves short by making the same mistakes over and over again it is a learning experience for a lot of these guys but from where we started against Derbyshire, which was an appalling performance given the standards we set, we have gone from strength to strength."