No 8 Angus Schaw chimed in with 40 as well, including six fours and a lusty six.
The Jacob Smith-led Bay team, who won the Chapple Cup last month, were predominantly without their rash of CD players.
In Poverty Bay's innings, after they won the toss and chose to bat, brothers Sam Tallott, an opener, was 80 not out with 11 boundaries and No 3 Scott Tallott scored 71 runs.
While wicket-less, Complete Flooring Napier Technical Old Boys bowler Liam Rukuwai was the pick with 10 overs, six maidens and giving only nine runs. Smith snared 2-37.
"The two Cornwall boys got a partnership going and Seb, obviously, won the game for us.
"His cricket has said a lot of ability but he never transformed that into scores so he has today. He's played for this club [Cornwall] for four years and never scored 50 in club cricket so it's a big break for him today."
He praised Ruahine Motors Central Hawke's Bay batsman Schaw but impressed the Bay had a lot of batting depth.
"Liam top scored for Tech in our club game yesterday [report below] and Henry Hunter, who opens batting for Central, is batting at 10," Dale said, stressing the top order who missed out could make up for it in this weekend's first Hawk Cup qualifying match.
"I'm trying not to sound arrogant here but we needed some competition for an ideal preparation for next week," he said, adding the Bay men struggled to see the red ball in the trees as it got dark with rain at a magnificent venue.