But he would have needed a near-miracle of six sixes in the last over to surpass Ngatapa's total.
HSOB captain Isaac Hughes won the toss and opted to bowl.
Opening bowler Glen Udall (two wickets for 19 runs off six overs), off-spinner Simon Blaker (2-39 off 6) and seamer Theron (1-42 off 6) were the wicket-takers as Ngatapa grafted hard to finish at 167-6.
First-drop Jeremy Castles was the stand-out. His 56 from 76 balls in 111 minutes was a controlled knock notable for his quick and sure footwork.
Simon Wilson (34 off 28) and Gibson (23 off 14), provided Castles with excellent support.
Gibson swept powerfully against Blaker but the offie finished his spell creditably, having bowled an attacking line throughout.
HSOB started solidly. Ollie Needham (28) and Udall (36) put on a 59-run opening partnership before Ngatapa claimed the prize wicket of Udall halfway through the 13th over.
Udall top-edged the ball from an attempted pull shot from the bowling of Grant Walsh and Jack Jefferd took the vital catch at backward square leg.
Walsh (4-22 off 6) and off-spinning compatriot Castles (3-21 off 5) applied immense pressure with good line and length and clever change of pace.
There was even a bit of comedy relief in the form of a Castles no-ball that bounced twice on its way to the striker.
No.7 Jeff Chambers played a busy hand for 21 off 27 balls. He placed the ball well in a gritty 27-run stand with Theron for the sixth wicket.
Both ran hard but the rate of scoring required quickly became double-figures, too much for HSOB to chase down, and Ngatapa were once again worthy champions.