Hunter scored 70 runs before mistiming Meehan to Craig Herrick but 214 from 49.4 overs desperately demanded Hindmarch stay in for a stronger finish and a challenging total.
NTOB captain George Diack put it down to their "best game of fielding in a long time".
"It's not won on the bat or the ball. It's won on fielding," Diack said, hurting himself saving a boundary off Hunter before demoting himself to No 10 in the batting order.
NTOB eclipsed the target with 216-7 with 9.1 overs to spare.
Matt Edmondson scored 61, Liam Rukuwai added 52 and Stevie Smidt, who got 4-51, was 49 not out.
In the other semifinal, Heretaunga Building Society Cornwall avenged their Gifford Devine Bat defeats with a convincing 65-run victory over hosts Havelock North CC at Anderson Park.
Cornwall batsman Michael Taiaroa laid the foundation for the 277-6 with 125, including 12 fours and three sixes from 138 balls.
Captain Jacob Smith added 46 and Jonathon Hall was unbeaten on 45.
Kurt Richards took 3-43.
For Havelock, Graeme Tryon top-scored with 53 while Ben Jackett claimed 3-33 and Jayden Wiggins 3-47 but Hall was the most frugal at 1.84 an over.
Cornwall manager Neil Jackett said the game went to plan as the wheels slowly but surely came off the villagers.
"It was a good little revenge game," Jackett said of the defending champions who also beat NTOB at Nelson Park in the last round.
Cornwall pulled off a Houdini act last summer, beating favourites NTOB on an artificial wicket at Park Island, Napier, after rain made grass pitches unplayable.
Havelock skipper Todd Astill bemoaned a poor bowling effort from his troops.
"We had one four ball an over and conceded 20 wides," Astill said, whipping his gloves off to finish three balls for injured Chris Sole but ended up rolling his arm for 9.3 overs.
"Mikey Taiaroa batted well and didn't give us a chance," he said, happy to finish well above Taradale CC and NOBM and a few points shy of Cornwall in fourth place for the overall points title.
Cornwall's third and fourth grade Lions teams are also in this Saturday's finals, emulating the club's feat in 2009 when the premiers and thirds were champions and the fourths settled for runners-up.