North Devon scored more runs in the same number of overs as Exeter on the County Ground, but lost by 33 runs once Duckworth-Lewis was brought into play.
Alex Barrow (61) and Ben Green (35) top scored for Exeter, and Tom Richardson made 29, in a 33-over total of 165, which was revised upwards to 212 by DLS.
Devon paceman Jack Popham had two for 21.
The DLS system makes provision for the potential runs scored had the game not been rain affected – and this one certainly was.
By the time the teams came off at the end umpires Phil Mallett and Roger Tolchard had restarted the game on six occasions.
Tom Popham (36) had the only score of note early on as North Devon laboured to 40 for four. Kiwi Phil Mecredy (2-24) and Tom Baycock (2-34) did the damage.
Rob Gear (67) and Steffan James (26no) helped North Devon to 179 for five in 33 overs, which wasn’t enough.
North Devon are sixth in a table of ten: 40 points clear of the relegation places and 53 behind leaders Sidmouth.
North Devon head to Plymouth this Saturday, a side that has won six of its last seven starts.
“I’m expecting a tough game against a side that seem to have gathered a lot of momentum since we played them earlier in the season,” said North Devon skipper Matt Westaway.
North Devon are set to welcome Dan Bowser back for Saturday’s trip to Plymouth, with the batsman missing the match against Exeter.
Tom Popham is unavailable, as is Alfie Huxtable. Jack Hockin and Rikki Kelly will come in to replace them.