However, the run rate changed when Ryder, batting at five after moving to NOBM from Napier Tech, came to the wicket.
At 59/4, Ryder was joined by Sinclair. The pair put on 66 in quick time, most coming from Ryder's bat.
When Sinclair departed for 23, caught by Wiggins from spinner Graeme Tryon, NOBM had accelerated their run rate to just under four an over with 125/5 off 32 overs, and looked poised for a decent finish.
However, opening bowler Liam Dudding grabbed the key wicket of Ryder, who ended with 90 off 64 balls, including 8 fours and 6 sixes.
OBM were all out in the 47th over, for 189.
Dudding was Cornwall's most economical bowler, with 2-26 off his 10.
Off spinner Tryon, after 5-29 against Taradale last week, again grabbed wickets, finishing with 4-52 off 10 overs,. Liam Hill chipped in with 3-51.
Wiggins started his innings strongly, with consecutive fours off the first two balls from Josh Paerau, and proceeded to gather runs at roughly a run-a-ball.
Mitch Hammond offered support with 24 off 55 balls, but it was Wiggins' day, ending the match in the 40th over on 108no, after hitting Sinclair for six.
At Forest Gate Domain in Ongaonga, Ruahine Motors Premiers CHB were too strong for Bayleys Taradale on a damp pitch that improved through the day.
CHB's top order were consistent, with Jake Smith (43), opening round century maker Scott Schaw (52) and Josh Clarkson (53) all getting runs. A late flurry from Dominic Thompson (28 off 21) helped CHB through to 236/6.
Opening the bowling, Clarkson pinned Taradale down early, and snared two top order wickets on his way to 2-9 off six overs.
Only captain Josh Jones (22) offered resistance for Taradale, who were all out for 62 in the 30th over.
Angus Schaw was CHB's best bowler with a productive and tight 4-13 off 7.5.
And at Nelson Park, Reynard Health Supplies Havelock North must have wondered if 171 off 50 overs was enough against defending champs Innovate Electrical Premier Napier Technical Old Boy.
Havelock's top order accumulated runs with Sam Ferguson (26) and Angus Henderson (38) getting solid starts. Jack Hammond (24) and Harry Ghodke (31no) were other key contributors.
Ghodke also shone with the ball, grabbing Napier Tech openers Matt Edmondson (10) and Izaiah Lange (11) en route to 3-16.
Bronson Meehan (36) and Todd Watson (35) fought back but Havelock's tight bowling, including a miserly 1-15 off 10 from Riyan Perera meant the chase was always a challenge for Napier Tech, who were all out for 135 in the 45th over.
William Clark's 4-29 was Havelock's best bowling return.