The Duckworth-Lewis Method left NTOB hosting Ruahine Motors Ford Central Hawke's Bay (CHB) at Nelson Park this Saturday by the skin of their teeth in the other semifinal.
Cornwall made short work of the villagers for a paltry 67-9 runs in 17.3 overs with Phil Hammond not batting.
Only opener Jared Priest showed some resistance, with 22 runs from as many balls as Liam Dudding ripped through the order to finish with 6-21 from nine overs, including three maidens.
Cornwall skipper Jacob Smith won the toss and chose to bowl with the threat of inclement weather.
"The pitch was keeping a bit low but it was a pretty good deck," Smith said after he and fellow opening batsman Seb Langridge eclipsed the total with 68 runs in 5.4 overs.
Both scored from 17 balls for the maximum nine points.
Langridge carved up 39 runs, including nine fours, while Smith racked up 27, including four boundaries.
Smith revealed he had told players they were unlikely to play but in the 11th hour called up some seniors to make 11.
"We're happy it didn't happen so easily," he said, as Cornwall watched the NTOB result unfold.
Smith is hoping to boost their stocks with university players returning this Saturday, weather permitting, from Auckland, Hamilton, Wellington and Palmerston North.
CHB taking nine points away against Sharpies Driving Range Taradale CC with a six-wicket victory made NTOB sweat.
"It came down to something like 0.1 on the net run rate," NTOB player George Diack said.
"We were sitting upstairs quietly sipping beer so when the run rate came through we had a faint smile."
Diack said NTOB were guilty of taking things for granted, coming into the weekend perched on the top rung.
"We also won the toss and chose to bat. It's not the best thing to do when it's a greenish, seaming wicket."
Retired CD record-holder/NOBM batsman Mathew Sinclair looked settled for the long haul after NTOB were skittled for 178 in a mere 33.1 overs.
Captain Morten Freer top scored with 55 runs but NOBM first-change bowler Ollie Sutton was outstanding to finish with 4-35 in 10 overs, including a maiden.
Sean Daniels took 2-49 from 10 and Brendon Quinn claimed 3-37 but wasn't as frugal.
No 3 Sinclair was 67 not out from as many balls, including 10 boundaries, as NOBM chased a Duckowrth-Lewis Method target of 74 in 23.2 overs when rain abandoned play.
"We weren't getting him out although he did nick one early but the umpire said it came off his pad.
"Skippy's Skippy [Sinclair] and he's beautiful to watch and he's one of the best batsmen in New Zealand," Diack said, mindful had they got his scalp they would have fancied their chances of rolling NOBM.
He said NOBM had eclipsed the DL Method target in nine overs as he and Jayden Lennox helped slow down the collateral damage.
While NTOB's record against CHB hasn't been the best this summer (losing twice), Diack said it was do-or-die time and they were happy to be hosting the third placegetters at Nelson Park in the semifinal.
For Taradale, No 3 Lance Sivewright (44 runs), Callum Hewetson (32 runs) and No 6 Luke Kenworthy (30) offered resistance but CHB spinner Angus Schaw took 3-31 from 10 overs, including a maiden.
Jake Chalmers (2-42) and Charlie Robson (1-22) also were miserly.
In reply, the Brendon Bracewell-coached CHB got home 159-4 in 30.3 overs.
Opener James Mackie scored 59 and No 3 Will Chapples added a crisp 54 from 51 balls.
Spinner Chiweshe Tafadzwe Mpofu and opening seamer Ben Stoyanoff kept things on the leash for a while.
