But Clarkson (28* off 14) and Willem Ludick (23* off 12) continued the barrage to take the hosts home with an over to spare.
Earlier it had been another strong batting display by the Volts with Hamish Rutherford (41 off 19) and Nick Kelly (45 off 24) having the Volts well placed for a 200-plus score.
When Ajaz Patel dismissed Kelly in the 14th over it was the start of a Stags fightback, chipping away with wickets and tight overs to hold the Volts to 184-7. Noema-Barnett was also influential with the ball, finishing his spell with 1-26.
The win moves the Stags up to third on the ladder and the Volts remain on top. The Stags head to Auckland for an important clash with the fourth-placed Aces today, while the Volts will host the Wellington Firebirds in Dunedin on Monday.
Meanwhile, Eden Carson starred with 5-18 to lead the Otago Sparks to a convincing 72-run win over the Central Hinds in their Dream11 Super Smash match at McLean Park.
With an impressive 181-3 on the board after electing to bat first the teenager ran through the Central Hinds batting to snare her first five-for. The Hinds were always well behind the asking rate and were all out for 109 in the 20th over.
Australian allrounder Amanda-Jade Wellington continued her excellent form with bat and ball. She returned 2-20 off her four overs of leg spin and hit 19* off just 8 balls at the end of the Sparks innings to ensure a daunting target was set.
The Sparks batters all fired with Hayley Jensen (55 off 38 balls) the standout. Millie Cowan batted through the 20 overs for an unbeaten 50 from 49 balls and Suzie Bates got the innings off to the ideal start with 31 off 20.
Hannah Rowe (3-36) was the sole wicket-taker for the Hinds on a day where the Sparks controlled the match throughout.
With three successive wins, the Sparks have moved into third spot on the competition ladder while the Hinds drop to fourth. Both sides are well in the hunt for playoff berths heading into their final two matches in the round-robin.