City's Zac Khawaja smashed a century in the opening round of the Lion Red Cup at Kensington Park, dashing Onerahi's hopes of starting off from where they left off last year.
Khawaja scored 132 from 141 balls, which included a whopping 15 fours and four sixes, as City combined to set Onerahi 300 from their 50-overs - and eventually win by 174 runs.
Opening the batting, Khawaja and Joey Yovich put on 51 before Yovich (29 off 20) lost his wicket to Dillon Lees on Saturday.
However, it was the second wicket partnership between Khawaja and captain Ian Page which did the damage. Page and Khawaja progressed the score through to 169 before Page was removed for 46 in the 32nd over.
A tidy 32 off 30 by Steve Morris and a quick-fire 23 off 15 from Kieran Nelson helped push City through to 299 for 8 after their full complement.
The pick of the bowlers for Onerahi was Tom Herman who produced figures of 2 for 50 off nine overs. Also chipping in with a brace of wickets was Lees who finished with 2 for 66 off eight.
In response, Onerahi could only manage a total of 125 all out inside 37 overs.
Doing the damage for City with the ball was Yovich who showed his class with 4 for 28, including three maidens.
Page also chipped in with 3 for 43 off 10 overs as Onerahi struggled to put together a partnership in what was a tough first up match.
Showing his usual grit, Brad Kneebone produced a steady 59 (off 109) before being caught and bowled by Page in the 30th over.
Of concern for City would be the 26 extras they leaked, seven of which belonged to Page.
In the other 50-over matches, Kaipara Flats snuck home against Zest Insurance Whangarei Boys' High School by 47 runs.
After posting 170 for 9, Kaipara managed to bowl Boys' High out for 123 inside 38 overs. Wicketkeeper-batsman Rory Christopherson was the best for Kaipara, scoring a measured 51 off 92 balls.
With the ball, New Zealand representative Kurtley Watson caused havoc in taking 3 for 21 off nine. Meanwhile, for Kaipara, Matt Taylor claimed an impressive 5 for 20 off 8.4 overs to essentially give his side the win.
In the final club cricket match of the weekend, Maungakaramea cruised home against Kamo as they won by six wickets.