Essex 307 for 6 (Chopra 83, Cook 54) beat Kent 50 for 3 by 57 runs (DLS method)
Essex landed their seventh win in eight starts and marched through to the Royal London Cup semi-finals following a 57-run triumph on the Duckworth/Lewis/Stern method over South Group wooden-spoonists Kent.
In pursuit of the visitors' 307 for 6, Kent had slumped to 50 for 3 after 11 overs when the rain, that had already wiped out the day's three other group games in the south east, arrived abruptly to end proceedings and inflict a seventh defeat upon the basement hosts.
Kent opened their reply with in-form Daniel Bell-Drummond and former Tonbridge School prodigy Zak Crawley, who was making his first-team debut. In fast-fading light and with rain on the way Crawley, in attempting to force the pace, clipped one off his stumps from Jamie Porter only to pick out Varun Chopra at deep square leg and march off for 2.
With his side already 30-odd behind on the asking rate, Kent skipper Sam Northeast smeared across the line to be bowled by Ashar Zaidi.
Zaidi struck in his next over by snaring Sean Dickson lbw on the back foot, bringing in Alex Blake, who lightened Kent gloom with three, quick boundaries before the rain intensified to end proceedings just before 6.30pm.
Batting first after winning the toss, the Essex top-order rock that is Alastair Cook swept to a comfortable run-a-ball 50 and, in the process, moved past the 500-run milestone at an average of almost 72 in this season's RLODC qualification campaign.
Cook contributed 54 to an opening stand of 95 with Varun Chopra before he lent back to cut the fifth ball of the game from left-arm spinner Imran Qayyum, only to edge into the gloves of Adam Rouse.
Chopra posted a 25th half-century in the format from 76 balls and appeared destined for three figures until he chopped on when also aiming a late cut against Qayyum to go for 83.
Callum Haggett accounted for Tom Westley to a catch behind when the Essex right-hander steered an attempted run-down to third man off the bat face and straight to the keeper.
Dan Lawrence hit the first six of the day in the 40th over when he reverse-swept one from Qayyum over the ropes at backward point endangering the replacement St Lawrence lime tree.
But, in the quest for late runs, Lawrence perished with 32 to his name, driving on the up against Ivan Thomas he picked out Bell-Drummond tumbling to his right at mid-off.
After a quickfire 22, Zaidi holed out to long-on to gift Charlie Hartley a wicket, then Ravi Bopara, on 49, sliced to backward point to give Haggett and second scalp.
Qayyum also bagged two, albeit at a cost of 79 runs after Kent - without a hope of qualification and having bid farewell to their overseas player Wayne Parnell - opted to rest six other first-choice regulars and give a first-team debut to teenage batsman Crawley and a domestic List A bow to Qayyum.