During the first half Napier had 79 per cent of the possession and 60 per cent of the territory, while in the second half it was 66 per cent and 59 per cent against the regular National Top Four finalists.
Those figures are just some of the positives NBHS can take into their quest for a Top Four berth, which will continue with a home Hurricanes region knockout game against St Pats Town on August 25.
"It was pretty disappointing. We let them have some easy tries and gave them easy opportunities early on," captain Thompson said afterwards.
His twin brother, centre Leo Thompson, who was judged player of the match, was a little more accurate with his summation.
"We slacked off in the second half after starting off well. We've still got a lot to work on and there's still the Top Four to aim for," he said.
Hamilton, who shared the Super 8 title with Hastings Boys' High School last year, turned down two easy three-pointers in the first three minutes and were rewarded for their patience when No 8 Dion Keogh scored a pushover try in the fifth minute.
Napier opened their account with a 13th-minute try to Leo Thompson after good work from fullback Max Anderson. The visitors took the lead in the 24th minute when busy No 8 Luke Russell scored from a lineout drive.
Superb patience and ball retention resulted in Napier tighthead prop Patrick Teddy scoring in the 33rd minute. Second five-eighth Keegan Christian-Goss added the conversion and the visitors led 17-5 at the interval.
Five minutes into the second half, Hamilton turned down a three-pointer chance and opted for a scrum. From a set-piece move centre Josh Calvert scored and Murray added the conversion to have the hosts narrow the gap to 17-12.
Fijian winger Leweni Mocekaca raced 64 metres for a try to tie the game up in the 46th minute and a 54th-minute penalty from Murray put Hamilton ahead for the first time at 20-17.
Napier regained the lead in the 59th minute when flanker Sam Henderson exposed some fragile defensive work from Mocekaca to score in the corner.
At the business end of the clash, Hamilton retained possession well and put Napier under enough pressure to force them into conceding a penalty, which proved the killer blow.
While Leo Thompson deserved the player of the match award, he must have been pushed close by Teddy who had a massive workrate, carrying with purpose and tackling tirelessly.
"I had a pretty good game but the result was gutting. While that display will give us a bit of confidence we still need more accuracy at the breakdown and more communication on defence," Teddy said.
"I'm pretty proud of the boys. Yes we left a few points out there today but that's rugby."
Captain Thompson and Russell also showed why they were selected for the Hurricanes under-18 camp last month.
In the Hamilton pack, captain and blindside flanker Tom Martin, Keogh and lock Josh Lord were inspirational. Halfback Cortez-Lee Ratima was just as classy as he was in the previous week's 26-0 win against Hastings Boys' High School.
"We knew we had to hold on to the ball. We stuck to our structures and weathered a tough storm," a delighted Martin said afterwards.
Scorers:
Hamilton BHS 23 (Dion Keogh, Josh Calvert, Leweni Mocekaca tries; Demante Murray 2 pens, con), NBHS 22 (Leo Thompson, Luke Russell, Patrick Teddy, Sam Henderson tries; Keegan Christian-Goss con). HT: Napier 17-5.