PLYMSTOCK’S winning run came to a halt at Thorverton where they dipped out by four wickets to the form side of the division.
Jason Williams made his fourth successive league score of 50 or more in a Plymstock total of 213 all out.
Thorverton knocked off the runs with eight balls to spare, Kobi Griggs making 43 and Dave Baldock 38.
Defeat drops Plymstock down from second to third in an all-change top three.
Chudleigh are the new leaders after beating Ipplepen, who were top but are now second.
Skipper Scott Mansfield said there were lessons to be learned from a defeat which was a setback but not a disaster.
“The game was one that could have gone either way but a total of 169 balls not scored off during our innings, and possibly our worse fielding performance this year, resulted in defeat with one over to go,” said Mansfield.
“What we didn't do was hold on to catches, which is probably the first time this year.
“A few early chances went down and when the game got tight we bowled too many four balls which relieved the pressure.
“We always felt in the game until Andy Pitt came in and took on the spin which took the game away when things were getting tight towards the end.
“With results as they have been all season things haven't really changed so we will take this as a wake-up call after our recent run of wins with some very big games coming up, starting with a tricky derby date with Ivybridge.”
Williams with 62 off 101 balls helped Plymstock reach 156 for four in the 34th over. Along the way he put on 74 with Seb Jordan (39) and 51 with Mansfield (59).
Mansfield was ninth out in the penultimate over.
Gill Crouch (3-44) was the leading wicket taker, although four Plymstock batsmen ran themselves out. Griggs (1-22) kept it tight in his nine overs.
Thorverton lost opener Jamie Khan lw in the first over to Nick Lowe, but soon got over it as Paul Fielder (35) and Griggs (43) put on 78.
Baldock (38) and James Hope (31) got the target down to 36 in seven overs, which Pitt (26no) and Harry Choules (19no) achieved with time to spare.
Jack Horton with three for 47 had the most wickets for Plymstock. Lowe and Dom Wood bowled tidily.
“We paced it well and it was never in any doubt once we got to 177 for six,” said skipper Graham White.
“The good thing was everyone chipped in one way or another. The wickets were shared between four bowlers and we also had the four run-outs – good stuff to see.
“Apart from losing Jamie Khan rather early, and myself to a run-out, we batted well and always had the situation under control.”
Thorverton visit former leaders Ipplepen this Saturday. Pens were knocked off the top by Chudleigh in the last round of games.